The problems of today are the same as the problems of yesterday, just with bigger numbers. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP ----- Original Message ----- From: "Mel Beckman" <mel@beckman.org> To: "Mike Hammett" <nanog@ics-il.net> Cc: "NANOG" <nanog@nanog.org> Sent: Tuesday, January 3, 2023 10:57:34 AM Subject: Re: SDN Internet Router (sir) It’s not a problem, due to cheap, plentiful high-speed memory and rapid prefix search silicon in backbone routers. The entire Internet routing table consumes at most a few gigabytes when fully structured (and only a few hundred Mbytes stored flat). That’s less memory than your average laptop sports. Even in the worst case scenario, where every network decides to announce only its most specific prefixes, the BGP backbone would temporarily enter an oscillating state that generates a large number of routing updates into the inter-domain routing space. In this case, BGP route damping will quickly suppress the crazies while the backbone stabilizes. Small routers should not be taking full tables, since there is no point to them being in the default free zone. For large routers, neither memory nor CPU speed are an issue. High-speed routers operating in the default-free zone have a critical path in the forwarding decision for each packet: it needs to take less than the inter-packet arrival time for minimum-sized IP packets. This is easy to achieve with today’s hardware. A router line card with an aggregate line rate across all of its point-to-point interfaces of 10Tbps (readily available in today’s gear) can process packets with just a handful of cycles in the FIB Ternary Content Addressable Memory (TCAM) using ASIC-assisted lookups. TCAM is the most expensive component you’re paying for in such a router. It’s not cheap, but backbone routers don’t need to be cheap. They just need to not be memory-constrained. -mel via cell On Jan 3, 2023, at 7:47 AM, Mike Hammett <nanog@ics-il.net> wrote: <blockquote> https://github.com/dbarrosop/sir I came across this over the weekend. Given that the project was abandoned six years ago, are there any other efforts with a similar goal (more intelligently placing routes into FIBs of low-FIB capacity devices? ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP </blockquote>

Disagree that it’s a line in the sand. It’s use the right tool for the job. If a device is low FIB, it’s that way for a reason. There are plenty of ways to massage that with policy and software, depending on capabilities , but at the end of the day, trying to sort 10 pounds of shit to store in a 5 pound bag is eventually going to end up the same way. On Tue, Jan 3, 2023 at 13:18 Mike Hammett <nanog@ics-il.net> wrote:

There are likely more networks with 10 gigabit or less total external capacity than there are with more.

Creating imaginary lines in the sand doesn't really help anyone.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------ *From: *"Mel Beckman" <mel@beckman.org> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"NANOG" <nanog@nanog.org> *Sent: *Tuesday, January 3, 2023 10:57:34 AM *Subject: *Re: SDN Internet Router (sir)

It’s not a problem, due to cheap, plentiful high-speed memory and rapid prefix search silicon in backbone routers. The entire Internet routing table consumes at most a few gigabytes when fully structured (and only a few hundred Mbytes stored flat). That’s less memory than your average laptop sports.

Even in the worst case scenario, where every network decides to announce only its most specific prefixes, the BGP backbone would temporarily enter an oscillating state that generates a large number of routing updates into the inter-domain routing space. In this case, BGP route damping will quickly suppress the crazies while the backbone stabilizes.

Small routers should not be taking full tables, since there is no point to them being in the default free zone. For large routers, neither memory nor CPU speed are an issue. High-speed routers operating in the default-free zone have a critical path in the forwarding decision for each packet: it needs to take less than the inter-packet arrival time for minimum-sized IP packets.

This is easy to achieve with today’s hardware. A router line card with an aggregate line rate across all of its point-to-point interfaces of 10Tbps (readily available in today’s gear) can process packets with just a handful of cycles in the FIB Ternary Content Addressable Memory (TCAM) using ASIC-assisted lookups. TCAM is the most expensive component you’re paying for in such a router. It’s not cheap, but backbone routers don’t need to be cheap. They just need to not be memory-constrained.

-mel via cell

On Jan 3, 2023, at 7:47 AM, Mike Hammett <nanog@ics-il.net> wrote:

 https://github.com/dbarrosop/sir

I came across this over the weekend. Given that the project was abandoned six years ago, are there any other efforts with a similar goal (more intelligently placing routes into FIBs of low-FIB capacity devices?

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg>

Christopher Morrow wrote:

Some of the reasoning behind 'i need/want to do SDN things' is 'low fib device' sort of reasonings.

What? SDN is a poor alternative for those who can't construct a network with fully automated QoS guarantee. Even with SDN, QoS guarantee implies QoS routing requiring dedicated routing table entry for each flow, which will not shrink but bloat routing tables regardless of whether you call it FIB or not. Masataka Ohta

Matthew Walster wrote:

SDN does not imply QoS routing,

As long as the shortest path is comfortable enough, no, it does not have to.

it's just one aspect of it. Some use it for classifying guest traffic etc.

If special path is provided for guest or otherwise prioritized traffic, that's QoS routing. Anyway, prioritization needs more, not less, routing table entries. Masataka Ohta

Matthew Walster wrote:

No... It's action based. You can send it a different route, you can replicate it, you can drop it, you can mutate it...

Replication is a poor alternative for multicast. For other actions, why, do you think, they are performed? Just for fun? Or to differentiate treatment of some packets, that is, prioritization?

You can send it to a different destination for stateful filtering when it doesn't match an expected pattern!

Unless pattern is as simple as having certain port number, stateful filtering almost always needs all packets including those matching expected pattern, I'm afraid.

SDN is not just QoS routing, please stop saying that.

See above.

Nope, not true. Had 1000 routes, only 100 available in FIB. So you filter to the top 50 doing traffic and default route the rest of the traffic. Less entries.

If default route is acceptable, just rely on it along with 50 non default routes with plain IP routers. Masataka Ohta

Matthew Walster wrote:

...

...

No... It's action based. You can send it a different route, you can replicate it, you can drop it, you can mutate it...

Replication is a poor alternative for multicast.

You conveniently ignore things like IDS, port mirroring, things like that.

Wrong. Instead, you conveniently ignore that such forwarding requires a link between an SDN router and a monitoring device have the same or larger MTU than an incoming link of the SDN router, which means the router and the monitoring device must be tightly coupled effectively to be a single device. Sometimes, packet loss possibility between them often requires they must actually be the same device.

No. There are far more actions than for prioritisation.

Just for fun? I'm afraid I already mentioned so.

What if you want to make sure certain classes of traffic do not flow over a link, because it is unencrypted and/or sensitive, but you're happy to send as much TLS wrapped data as you like?

You are wrongly assuming TLS wrapped packets can be identified packet by packet, as I wrote:

...

Unless pattern is as simple as having certain port number, stateful filtering almost always needs all packets including those matching expected pattern, I'm afraid.

So?

What if you want to sample some flows in an ERSPAN like mechanism?

See above for MTU issues.

What if you want to urgently drop a set of flows based on a known DDOS signature?

Urgently? Even though a DDOS signature is known in advance? Why?

...

Unless pattern is as simple as having certain port number, stateful filtering almost always needs all packets including those matching expected pattern, I'm afraid.

Or a certain set of IP addresses. Policy based routing.

That's even simpler than port number to be treated by having or not having proper routing table entries.

...

If default route is acceptable, just rely on it along with 50 non default routes with plain IP routers.

That's what OP is suggesting.

With plain IP routers?

That's what SIR is. Classifying prefixes by traffic and only keeping the ones with the highest volume of traffic, discarding the rest, relying on the default route to infill.

Given the connectionless nature of the Internet, route change based on volume of traffic averaged over certain period of time is rather harmful than useful. Masataka Ohta

" With plain IP routers?" Yes, or, well, relatively plain, depending on the implementation. The originally linked project used Arista. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP ----- Original Message ----- From: "Masataka Ohta" <mohta@necom830.hpcl.titech.ac.jp> To: "Matthew Walster" <matthew@walster.org> Cc: "nanog list" <nanog@nanog.org> Sent: Saturday, January 7, 2023 8:44:59 AM Subject: Re: SDN Internet Router (sir) Matthew Walster wrote:

...

...

No... It's action based. You can send it a different route, you can replicate it, you can drop it, you can mutate it...

Replication is a poor alternative for multicast.

You conveniently ignore things like IDS, port mirroring, things like that.

Wrong. Instead, you conveniently ignore that such forwarding requires a link between an SDN router and a monitoring device have the same or larger MTU than an incoming link of the SDN router, which means the router and the monitoring device must be tightly coupled effectively to be a single device. Sometimes, packet loss possibility between them often requires they must actually be the same device.

No. There are far more actions than for prioritisation.

Just for fun? I'm afraid I already mentioned so.

What if you want to make sure certain classes of traffic do not flow over a link, because it is unencrypted and/or sensitive, but you're happy to send as much TLS wrapped data as you like?

You are wrongly assuming TLS wrapped packets can be identified packet by packet, as I wrote:

...

Unless pattern is as simple as having certain port number, stateful filtering almost always needs all packets including those matching expected pattern, I'm afraid.

So?

What if you want to sample some flows in an ERSPAN like mechanism?

See above for MTU issues.

What if you want to urgently drop a set of flows based on a known DDOS signature?

Urgently? Even though a DDOS signature is known in advance? Why?

...

Unless pattern is as simple as having certain port number, stateful filtering almost always needs all packets including those matching expected pattern, I'm afraid.

Or a certain set of IP addresses. Policy based routing.

That's even simpler than port number to be treated by having or not having proper routing table entries.

...

If default route is acceptable, just rely on it along with 50 non default routes with plain IP routers.

That's what OP is suggesting.

With plain IP routers?

That's what SIR is. Classifying prefixes by traffic and only keeping the ones with the highest volume of traffic, discarding the rest, relying on the default route to infill.

Given the connectionless nature of the Internet, route change based on volume of traffic averaged over certain period of time is rather harmful than useful. Masataka Ohta

I don't even know where this conversation has gone anymore. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP ----- Original Message ----- From: "Masataka Ohta" <mohta@necom830.hpcl.titech.ac.jp> To: "Mike Hammett" <nanog@ics-il.net> Cc: "nanog list" <nanog@nanog.org>, "Matthew Walster" <matthew@walster.org> Sent: Wednesday, January 11, 2023 7:00:07 AM Subject: Re: SDN Internet Router (sir) Mike Hammett wrote:

" With plain IP routers?"

Yes, or, well, relatively plain, depending on the implementation.

As completely plain routers have no difficulty to treat a default route, it is a waste of money and effort to try to have not so plain routers to do so regardless of whether the routers are SDN ones or not. Masataka Ohta

"The right tool for the job" gets into a religious argument in assuming that one's way to do the job is the only reasonable way to do the job. Large networks historically have a very poor (IMO) model of gigantic iron in a few locations, which results in sub-optimal routing for the rest of their network between those large POPs. I've heard time and time again that someone buying service from a major network in say New Orleans has a first hop of Dallas or Atlanta. I agree that full-route capable routers need to be in the large, central locations, but it isn't cost effective to have them at every POP, especially if you're a last-mile provider. I'd go into more examples of where it doesn't make sense to have full-route routers everywhere, but I'm afraid that the Internet would then focus on the examples instead of the core idea of intelligently putting routes into the FIBs of low-FIB routers throughout my network. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP ----- Original Message ----- From: "Tom Beecher" <beecher@beecher.cc> To: "Mike Hammett" <nanog@ics-il.net> Cc: "Mel Beckman" <mel@beckman.org>, "NANOG" <nanog@nanog.org> Sent: Wednesday, January 4, 2023 7:36:58 AM Subject: Re: SDN Internet Router (sir) Disagree that it’s a line in the sand. It’s use the right tool for the job. If a device is low FIB, it’s that way for a reason. There are plenty of ways to massage that with policy and software, depending on capabilities , but at the end of the day, trying to sort 10 pounds of shit to store in a 5 pound bag is eventually going to end up the same way. On Tue, Jan 3, 2023 at 13:18 Mike Hammett < nanog@ics-il.net > wrote: There are likely more networks with 10 gigabit or less total external capacity than there are with more. Creating imaginary lines in the sand doesn't really help anyone. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP From: "Mel Beckman" < mel@beckman.org > To: "Mike Hammett" < nanog@ics-il.net > Cc: "NANOG" < nanog@nanog.org > Sent: Tuesday, January 3, 2023 10:57:34 AM Subject: Re: SDN Internet Router (sir) It’s not a problem, due to cheap, plentiful high-speed memory and rapid prefix search silicon in backbone routers. The entire Internet routing table consumes at most a few gigabytes when fully structured (and only a few hundred Mbytes stored flat). That’s less memory than your average laptop sports. Even in the worst case scenario, where every network decides to announce only its most specific prefixes, the BGP backbone would temporarily enter an oscillating state that generates a large number of routing updates into the inter-domain routing space. In this case, BGP route damping will quickly suppress the crazies while the backbone stabilizes. Small routers should not be taking full tables, since there is no point to them being in the default free zone. For large routers, neither memory nor CPU speed are an issue. High-speed routers operating in the default-free zone have a critical path in the forwarding decision for each packet: it needs to take less than the inter-packet arrival time for minimum-sized IP packets. This is easy to achieve with today’s hardware. A router line card with an aggregate line rate across all of its point-to-point interfaces of 10Tbps (readily available in today’s gear) can process packets with just a handful of cycles in the FIB Ternary Content Addressable Memory (TCAM) using ASIC-assisted lookups. TCAM is the most expensive component you’re paying for in such a router. It’s not cheap, but backbone routers don’t need to be cheap. They just need to not be memory-constrained. -mel via cell <blockquote> On Jan 3, 2023, at 7:47 AM, Mike Hammett < nanog@ics-il.net > wrote: <blockquote> https://github.com/dbarrosop/sir I came across this over the weekend. Given that the project was abandoned six years ago, are there any other efforts with a similar goal (more intelligently placing routes into FIBs of low-FIB capacity devices? ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP </blockquote> </blockquote>

Then please bless the world with the right way. You acknowledge that not every router in a network needs to be fully DFZ capable, but then crap on my desire to have more than a default route in one. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP ----- Original Message ----- From: "Tom Beecher" <beecher@beecher.cc> To: "Mike Hammett" <nanog@ics-il.net> Cc: "Mel Beckman" <mel@beckman.org>, "NANOG" <nanog@nanog.org> Sent: Thursday, January 5, 2023 9:55:38 AM Subject: Re: SDN Internet Router (sir) "The right tool for the job" gets into a religious argument in assuming that one's way to do the job is the only reasonable way to do the job I disagree that it's religious. I completely agree there are locations in networks that having full DFZ capable routers doesn't make technical or economic sense. But there have long been different products for those different use cases. To perhaps explain my viewpoint better,(and perhaps I didn't properly comprehend the problem you're aiming to solve) : If you are trying to use SDN stuff to shuffle routes on and off a box because you have the wrong sized routers in place, then I would argue you're doing it wrong. If you are trying to use SDN stuff to (as Christopher mentioned) make decisions that are not strictly LPM, and the equipment you have cannot do that, then that's different and entirely reasonable. If the second use case is more of what you were asking, then I apologize for misunderstanding. On Thu, Jan 5, 2023 at 9:57 AM Mike Hammett < nanog@ics-il.net > wrote: <blockquote> "The right tool for the job" gets into a religious argument in assuming that one's way to do the job is the only reasonable way to do the job. Large networks historically have a very poor (IMO) model of gigantic iron in a few locations, which results in sub-optimal routing for the rest of their network between those large POPs. I've heard time and time again that someone buying service from a major network in say New Orleans has a first hop of Dallas or Atlanta. I agree that full-route capable routers need to be in the large, central locations, but it isn't cost effective to have them at every POP, especially if you're a last-mile provider. I'd go into more examples of where it doesn't make sense to have full-route routers everywhere, but I'm afraid that the Internet would then focus on the examples instead of the core idea of intelligently putting routes into the FIBs of low-FIB routers throughout my network. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP From: "Tom Beecher" < beecher@beecher.cc > To: "Mike Hammett" < nanog@ics-il.net > Cc: "Mel Beckman" < mel@beckman.org >, "NANOG" < nanog@nanog.org > Sent: Wednesday, January 4, 2023 7:36:58 AM Subject: Re: SDN Internet Router (sir) Disagree that it’s a line in the sand. It’s use the right tool for the job. If a device is low FIB, it’s that way for a reason. There are plenty of ways to massage that with policy and software, depending on capabilities , but at the end of the day, trying to sort 10 pounds of shit to store in a 5 pound bag is eventually going to end up the same way. On Tue, Jan 3, 2023 at 13:18 Mike Hammett < nanog@ics-il.net > wrote: <blockquote> There are likely more networks with 10 gigabit or less total external capacity than there are with more. Creating imaginary lines in the sand doesn't really help anyone. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP From: "Mel Beckman" < mel@beckman.org > To: "Mike Hammett" < nanog@ics-il.net > Cc: "NANOG" < nanog@nanog.org > Sent: Tuesday, January 3, 2023 10:57:34 AM Subject: Re: SDN Internet Router (sir) It’s not a problem, due to cheap, plentiful high-speed memory and rapid prefix search silicon in backbone routers. The entire Internet routing table consumes at most a few gigabytes when fully structured (and only a few hundred Mbytes stored flat). That’s less memory than your average laptop sports. Even in the worst case scenario, where every network decides to announce only its most specific prefixes, the BGP backbone would temporarily enter an oscillating state that generates a large number of routing updates into the inter-domain routing space. In this case, BGP route damping will quickly suppress the crazies while the backbone stabilizes. Small routers should not be taking full tables, since there is no point to them being in the default free zone. For large routers, neither memory nor CPU speed are an issue. High-speed routers operating in the default-free zone have a critical path in the forwarding decision for each packet: it needs to take less than the inter-packet arrival time for minimum-sized IP packets. This is easy to achieve with today’s hardware. A router line card with an aggregate line rate across all of its point-to-point interfaces of 10Tbps (readily available in today’s gear) can process packets with just a handful of cycles in the FIB Ternary Content Addressable Memory (TCAM) using ASIC-assisted lookups. TCAM is the most expensive component you’re paying for in such a router. It’s not cheap, but backbone routers don’t need to be cheap. They just need to not be memory-constrained. -mel via cell <blockquote> On Jan 3, 2023, at 7:47 AM, Mike Hammett < nanog@ics-il.net > wrote: </blockquote> <blockquote> https://github.com/dbarrosop/sir I came across this over the weekend. Given that the project was abandoned six years ago, are there any other efforts with a similar goal (more intelligently placing routes into FIBs of low-FIB capacity devices? ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP </blockquote> </blockquote> </blockquote>

On Thu, Jan 5, 2023 at 11:18 AM Mike Hammett <nanog@ics-il.net> wrote:

Initially, my thought was to use community filtering to push just IXes, customers, and defaults throughout the network, but that's obviously still sub-optimal.

I'd be surprised if a last mile network had a ton of traffic going to any more than a few hundred prefixes.

I think in a low-fib box at the edge of your network your choices are: "the easy choice, get default, follow that" "send some limited set of prefixes to the device, and default, so you MAY choose better for the initial hop away" you certainly can do the second with communities, or route-filters (prefix-list) on the senders, or.... you can choose what prefixes make the cut (get the community(ies)) based on traffic volumes or expected destination locality: "do not go east to go west!" these things will introduce toil and SOME suboptimal routing in some instances... perhaps it's better than per flow choosing left/right though and the support calls related to that choice. In your NOLA / DFW / ATL example it's totally possible that the networks in question do something like: "low fib box in tier-2 city (NOLA), dfz capable/core devices in tier-1 city (DFW/ATL), and send default from left/right to NOLA" Could they send more prefixes than default? sure... do they want to deal with the toil that induces? (probably not says your example). SDN isn't really an answer to this, though.. I don't think. Unless you envision that to lower the toil ?

Mike Hammett wrote:

I'm not concerned with which technology or buzzword gets the job done, only that the job is done.

Looking briefly at the couple of things out there, they're evaluating the top X prefixes in terms of traffic reported by s-flow, where X is the number I define, and those get pushed into the FIB. One recalculates every hour, one does so more quickly. How much is appropriate? I'm not sure. I can't imagine it would *NEED* to be done all of that often, given the traffic/prefix density an eyeball network will have. Default routes carry the rest. Default routes could be handled outside of this process, such that if this process fails, you just get some sub-optimal routing until repaired. Maybe it doesn't filter properly and sends a bunch of routes. Then just have a prefix limit set on the box. Maybe it sends the wrong prefixes. No harm, no foul. If you're routing sub-optimally internally, when it does hit a real router with a full FIB, it gets handled appropriately.

Unless it loops. The rest sounds nice. But flow caching got a bad rap back in the early worm days. But thats because the situation was a little worse back then. Cache the wrong routes or run out of cache, router dies. So long as thats not the case automating optimization is an extremely valuable goal.

I would just be looking for solutions that influence what's in the FIB and let the rest of the router work as the rest of the router would.

The problem comes when the router wont work at all without the FIB routes, like in the olden days.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentComputingSolutionsDeKalb><https://www.linkedin.com/company/intelligent-computing-solutions><https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><https://www.linkedin.com/company/midwest-internet-exchange><https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------------------------------------------------ *From: *"Christopher Morrow" <morrowc.lists@gmail.com> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Tom Beecher" <beecher@beecher.cc>, "NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 12:27:08 PM *Subject: *Re: SDN Internet Router (sir)

On Thu, Jan 5, 2023 at 11:18 AM Mike Hammett <nanog@ics-il.net <mailto:nanog@ics-il.net>> wrote:

Initially, my thought was to use community filtering to push just IXes, customers, and defaults throughout the network, but that's obviously still sub-optimal.

I'd be surprised if a last mile network had a ton of traffic going to any more than a few hundred prefixes.

I think in a low-fib box at the edge of your network your choices are: "the easy choice, get default, follow that"

"send some limited set of prefixes to the device, and default, so you MAY choose better for the initial hop away"

you certainly can do the second with communities, or route-filters (prefix-list) on the senders, or.... you can choose what prefixes make the cut (get the community(ies)) based on traffic volumes or expected destination locality: "do not go east to go west!"

these things will introduce toil and SOME suboptimal routing in some instances... perhaps it's better than per flow choosing left/right though and the support calls related to that choice.

In your NOLA / DFW / ATL example it's totally possible that the networks in question do something like: "low fib box in tier-2 city (NOLA), dfz capable/core devices in tier-1 city (DFW/ATL), and send default from left/right to NOLA"

Could they send more prefixes than default? sure... do they want to deal with the toil that induces? (probably not says your example).

SDN isn't really an answer to this, though.. I don't think. Unless you envision that to lower the toil ?

Mike, I’m not sure I understand what you mean by “suboptimal“ routing. Even though the Internet uses AS path length for routing, many of those path lengths are bogus, and don’t really represent any kind of path performance value. For example, a single AS might hide many hops in an MPLS network as a single hop, obscuring asymmetric routing and other uglies. Prepending also occurs when destinations are trying to enforce their own engineering policies, which often conflict with yours or mine. So what do you mean by “suboptimal“? Are you thinking that the “best” path in BGP tables actually meant you were getting a performance benefit? Because that’s definitely not the case in today’s Internet. Were were you thinking that you would be going along less congested paths? That’s really at the mercy of the traffic engineering of backbone providers over which we have no control. I generally populate local router FIBs to merel choose an exit point for purposes of load balancing, and nothing more. -mel On Jan 5, 2023, at 12:38 PM, Mike Hammett <nanog@ics-il.net> wrote:  I guess I wasn't around for those days. As far as running out, again, assuming the tooling works correctly, I'd think to target fewer routes than you could hold. Maybe 1k routes is all one would need to get a significant percent of the traffic. A lot of room to mess up if you can hold 100k, 500k routes. ----- Mike Hammett Intelligent Computing Solutions<http://www.ics-il.com/> [http://www.ics-il.com/images/fbicon.png]<https://www.facebook.com/ICSIL>[http://www.ics-il.com/images/googleicon.png]<https://plus.google.com/+IntelligentComputingSolutionsDeKalb>[http://www.ics-il.com/images/linkedinicon.png]<https://www.linkedin.com/company/intelligent-computing-solutions>[http://www.ics-il.com/images/twittericon.png]<https://twitter.com/ICSIL> Midwest Internet Exchange<http://www.midwest-ix.com/> [http://www.ics-il.com/images/fbicon.png]<https://www.facebook.com/mdwestix>[http://www.ics-il.com/images/linkedinicon.png]<https://www.linkedin.com/company/midwest-internet-exchange>[http://www.ics-il.com/images/twittericon.png]<https://twitter.com/mdwestix> The Brothers WISP<http://www.thebrotherswisp.com/> [http://www.ics-il.com/images/fbicon.png]<https://www.facebook.com/thebrotherswisp>[http://www.ics-il.com/images/youtubeicon.png]<https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ________________________________ From: "Joe Maimon" <jmaimon@jmaimon.com> To: "Mike Hammett" <nanog@ics-il.net>, "Christopher Morrow" <morrowc.lists@gmail.com> Cc: "NANOG" <nanog@nanog.org> Sent: Thursday, January 5, 2023 2:30:40 PM Subject: Re: SDN Internet Router (sir) Mike Hammett wrote:

I'm not concerned with which technology or buzzword gets the job done, only that the job is done.

Looking briefly at the couple of things out there, they're evaluating the top X prefixes in terms of traffic reported by s-flow, where X is the number I define, and those get pushed into the FIB. One recalculates every hour, one does so more quickly. How much is appropriate? I'm not sure. I can't imagine it would *NEED* to be done all of that often, given the traffic/prefix density an eyeball network will have. Default routes carry the rest. Default routes could be handled outside of this process, such that if this process fails, you just get some sub-optimal routing until repaired. Maybe it doesn't filter properly and sends a bunch of routes. Then just have a prefix limit set on the box. Maybe it sends the wrong prefixes. No harm, no foul. If you're routing sub-optimally internally, when it does hit a real router with a full FIB, it gets handled appropriately.

Unless it loops. The rest sounds nice. But flow caching got a bad rap back in the early worm days. But thats because the situation was a little worse back then. Cache the wrong routes or run out of cache, router dies. So long as thats not the case automating optimization is an extremely valuable goal.

I would just be looking for solutions that influence what's in the FIB and let the rest of the router work as the rest of the router would.

The problem comes when the router wont work at all without the FIB routes, like in the olden days.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentComputingSolutionsDeKalb><https://www.linkedin.com/company/intelligent-computing-solutions><https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><https://www.linkedin.com/company/midwest-internet-exchange><https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------------------------------------------------ *From: *"Christopher Morrow" <morrowc.lists@gmail.com> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Tom Beecher" <beecher@beecher.cc>, "NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 12:27:08 PM *Subject: *Re: SDN Internet Router (sir)

On Thu, Jan 5, 2023 at 11:18 AM Mike Hammett <nanog@ics-il.net <mailto:nanog@ics-il.net>> wrote:

Initially, my thought was to use community filtering to push just IXes, customers, and defaults throughout the network, but that's obviously still sub-optimal.

I'd be surprised if a last mile network had a ton of traffic going to any more than a few hundred prefixes.

I think in a low-fib box at the edge of your network your choices are: "the easy choice, get default, follow that"

"send some limited set of prefixes to the device, and default, so you MAY choose better for the initial hop away"

you certainly can do the second with communities, or route-filters (prefix-list) on the senders, or.... you can choose what prefixes make the cut (get the community(ies)) based on traffic volumes or expected destination locality: "do not go east to go west!"

these things will introduce toil and SOME suboptimal routing in some instances... perhaps it's better than per flow choosing left/right though and the support calls related to that choice.

In your NOLA / DFW / ATL example it's totally possible that the networks in question do something like: "low fib box in tier-2 city (NOLA), dfz capable/core devices in tier-1 city (DFW/ATL), and send default from left/right to NOLA"

Could they send more prefixes than default? sure... do they want to deal with the toil that induces? (probably not says your example).

SDN isn't really an answer to this, though.. I don't think. Unless you envision that to lower the toil ?

Mike, Thanks for that useful example. On a side note, Netflix is a thorn in all our sides :) You could put a localpref filter route to override the default for Netflix prefixes, but this impacts resilience. Since you peer with Netflix, I suspect we probably agree that Netflix’s ideas on traffic engineering are pretty one sided. I think it’s safe to say that BGP, which has scaled amazingly well, didn’t anticipate some of the big gorilla content systems. I don’t really see, though, how injecting FIB entries helps more than other methods. And as others have pointed out, the risk of creating routing loops is significant. Perhaps it is time to migrate to a new version of BGP. Projects like MBGP and FP-7‘s 4WARD are working on new follow-on routing models, but nothing is on the immediate horizon. I think we all thought we should finish IPv6 migration first :) -mel via cell On Jan 5, 2023, at 1:11 PM, Mike Hammett <nanog@ics-il.net> wrote:  I hesitated to get too specific in examples because someone is going to drag the conversation into the weeds. Let's take the the Dallas - New Orleans - Atlanta example where I have a connection from New Orleans to Dallas and a connection from New Orleans to Atlanta. Let's say I peer with Netflix in both markets. Netflix chooses to serve me out of Atlanta, for whatever reason. Say my default route sends my traffic to Dallas. That's not where Netflix wanted it, so now I have to go from Dallas to Atlanta, whether that's my circuit or across the public Internet. Potentially, it's on MPLS and it rides back through the New Orleans router to get back to Atlanta. That's a long trip when I already had a better path, the less-than-full-fib router just didn't know about it. Given that Netflix is a sizable amount of traffic in an eyeball ISP, that's a lot of traffic to be going the wrong way. If the website for Viktor's Arctic Plunge in Siberia was hosted in Atlanta, I wouldn't give two craps that the traffic went the wrong way because A), I'll probably never go there and B) when someone does, it won't be meaningfully enough traffic to accommodate. Someone's going to tell me to put a full-table router in New Orleans. Maybe I should. Okay, so maybe I have a POP in Ashford, Alabama. It has transport to New Orleans and Atlanta. There aren't enough grains of sugar in Ashford, Alabama to justify a current-generation, full table router. Now I'm even closer to Atlanta, but default may point to New Orleans. ----- Mike Hammett Intelligent Computing Solutions<http://www.ics-il.com/> [http://www.ics-il.com/images/fbicon.png]<https://www.facebook.com/ICSIL>[http://www.ics-il.com/images/googleicon.png]<https://plus.google.com/+IntelligentComputingSolutionsDeKalb>[http://www.ics-il.com/images/linkedinicon.png]<https://www.linkedin.com/company/intelligent-computing-solutions>[http://www.ics-il.com/images/twittericon.png]<https://twitter.com/ICSIL> Midwest Internet Exchange<http://www.midwest-ix.com/> [http://www.ics-il.com/images/fbicon.png]<https://www.facebook.com/mdwestix>[http://www.ics-il.com/images/linkedinicon.png]<https://www.linkedin.com/company/midwest-internet-exchange>[http://www.ics-il.com/images/twittericon.png]<https://twitter.com/mdwestix> The Brothers WISP<http://www.thebrotherswisp.com/> [http://www.ics-il.com/images/fbicon.png]<https://www.facebook.com/thebrotherswisp>[http://www.ics-il.com/images/youtubeicon.png]<https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ________________________________ From: "Mel Beckman" <mel@beckman.org> To: "Mike Hammett" <nanog@ics-il.net> Cc: "Joe Maimon" <jmaimon@jmaimon.com>, "NANOG" <nanog@nanog.org> Sent: Thursday, January 5, 2023 2:54:27 PM Subject: Re: SDN Internet Router (sir) Mike, I’m not sure I understand what you mean by “suboptimal“ routing. Even though the Internet uses AS path length for routing, many of those path lengths are bogus, and don’t really represent any kind of path performance value. For example, a single AS might hide many hops in an MPLS network as a single hop, obscuring asymmetric routing and other uglies. Prepending also occurs when destinations are trying to enforce their own engineering policies, which often conflict with yours or mine. So what do you mean by “suboptimal“? Are you thinking that the “best” path in BGP tables actually meant you were getting a performance benefit? Because that’s definitely not the case in today’s Internet. Were were you thinking that you would be going along less congested paths? That’s really at the mercy of the traffic engineering of backbone providers over which we have no control. I generally populate local router FIBs to merel choose an exit point for purposes of load balancing, and nothing more. -mel On Jan 5, 2023, at 12:38 PM, Mike Hammett <nanog@ics-il.net> wrote:  I guess I wasn't around for those days. As far as running out, again, assuming the tooling works correctly, I'd think to target fewer routes than you could hold. Maybe 1k routes is all one would need to get a significant percent of the traffic. A lot of room to mess up if you can hold 100k, 500k routes. ----- Mike Hammett Intelligent Computing Solutions<http://www.ics-il.com/> [http://www.ics-il.com/images/fbicon.png]<https://www.facebook.com/ICSIL>[http://www.ics-il.com/images/googleicon.png]<https://plus.google.com/+IntelligentComputingSolutionsDeKalb>[http://www.ics-il.com/images/linkedinicon.png]<https://www.linkedin.com/company/intelligent-computing-solutions>[http://www.ics-il.com/images/twittericon.png]<https://twitter.com/ICSIL> Midwest Internet Exchange<http://www.midwest-ix.com/> [http://www.ics-il.com/images/fbicon.png]<https://www.facebook.com/mdwestix>[http://www.ics-il.com/images/linkedinicon.png]<https://www.linkedin.com/company/midwest-internet-exchange>[http://www.ics-il.com/images/twittericon.png]<https://twitter.com/mdwestix> The Brothers WISP<http://www.thebrotherswisp.com/> [http://www.ics-il.com/images/fbicon.png]<https://www.facebook.com/thebrotherswisp>[http://www.ics-il.com/images/youtubeicon.png]<https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ________________________________ From: "Joe Maimon" <jmaimon@jmaimon.com> To: "Mike Hammett" <nanog@ics-il.net>, "Christopher Morrow" <morrowc.lists@gmail.com> Cc: "NANOG" <nanog@nanog.org> Sent: Thursday, January 5, 2023 2:30:40 PM Subject: Re: SDN Internet Router (sir) Mike Hammett wrote:

I'm not concerned with which technology or buzzword gets the job done, only that the job is done.

Looking briefly at the couple of things out there, they're evaluating the top X prefixes in terms of traffic reported by s-flow, where X is the number I define, and those get pushed into the FIB. One recalculates every hour, one does so more quickly. How much is appropriate? I'm not sure. I can't imagine it would *NEED* to be done all of that often, given the traffic/prefix density an eyeball network will have. Default routes carry the rest. Default routes could be handled outside of this process, such that if this process fails, you just get some sub-optimal routing until repaired. Maybe it doesn't filter properly and sends a bunch of routes. Then just have a prefix limit set on the box. Maybe it sends the wrong prefixes. No harm, no foul. If you're routing sub-optimally internally, when it does hit a real router with a full FIB, it gets handled appropriately.

Unless it loops. The rest sounds nice. But flow caching got a bad rap back in the early worm days. But thats because the situation was a little worse back then. Cache the wrong routes or run out of cache, router dies. So long as thats not the case automating optimization is an extremely valuable goal.

I would just be looking for solutions that influence what's in the FIB and let the rest of the router work as the rest of the router would.

The problem comes when the router wont work at all without the FIB routes, like in the olden days.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentComputingSolutionsDeKalb><https://www.linkedin.com/company/intelligent-computing-solutions><https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><https://www.linkedin.com/company/midwest-internet-exchange><https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------------------------------------------------ *From: *"Christopher Morrow" <morrowc.lists@gmail.com> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Tom Beecher" <beecher@beecher.cc>, "NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 12:27:08 PM *Subject: *Re: SDN Internet Router (sir)

On Thu, Jan 5, 2023 at 11:18 AM Mike Hammett <nanog@ics-il.net <mailto:nanog@ics-il.net>> wrote:

Initially, my thought was to use community filtering to push just IXes, customers, and defaults throughout the network, but that's obviously still sub-optimal.

I'd be surprised if a last mile network had a ton of traffic going to any more than a few hundred prefixes.

I think in a low-fib box at the edge of your network your choices are: "the easy choice, get default, follow that"

"send some limited set of prefixes to the device, and default, so you MAY choose better for the initial hop away"

you certainly can do the second with communities, or route-filters (prefix-list) on the senders, or.... you can choose what prefixes make the cut (get the community(ies)) based on traffic volumes or expected destination locality: "do not go east to go west!"

these things will introduce toil and SOME suboptimal routing in some instances... perhaps it's better than per flow choosing left/right though and the support calls related to that choice.

In your NOLA / DFW / ATL example it's totally possible that the networks in question do something like: "low fib box in tier-2 city (NOLA), dfz capable/core devices in tier-1 city (DFW/ATL), and send default from left/right to NOLA"

Could they send more prefixes than default? sure... do they want to deal with the toil that induces? (probably not says your example).

SDN isn't really an answer to this, though.. I don't think. Unless you envision that to lower the toil ?

I love that we can't even get a full week into the new year without beating the "let's overhaul BGP" drum. Some things never change. <3 Chris -----Original Message----- From: NANOG <nanog-bounces+chris.wright=commnetbroadband.com@nanog.org> On Behalf Of Joe Maimon Sent: Thursday, January 5, 2023 5:51 PM To: Mel Beckman <mel@beckman.org>; Mike Hammett <nanog@ics-il.net> Cc: NANOG <nanog@nanog.org> Subject: Re: SDN Internet Router (sir) And here is another interesting approach Ive left open in my browser window for who knows how long https://inog.net/files/iNOG14v_oliver_sourcerouting.pdf The problem with BGP is that local actors can exact global costs trivially by consuming as many routing slots as they can get away with, add together BGP path decisions and Most Specific traffic-engineering is the goto knob. Sometimes you just want to say this is the route, do not accept any more specifics, unless this route is no longer the route. But you want that done automatically and correctly, reliably. This is also why all the multi-homing approaches that do not involve global routing havent really taken off in any way to blunt table growth. And likely wont. See the aggregation factor in the routing report for how bad this is. There have been lots of BGP protocol and feature updates, but unless your going to uniformly run new systems and enterprise systems that support all of them, its hard to decide to build your entire routing strategy around them. That BGP unlike EIGRP never tried to tie together performance indicators with routing metrics feature or misdesign, you could debate that but it was always intentional. And opex has pretty much fallen down on the side of against IGP->BGP redistribution of prefixes, let alone performance metrics. That eBGP prefix has no good reliable way of indicating that an advertised route sucks so bad that you should never attempt to use it unless as last resort, thats why we have AS-paths wrapping screen lines. "finish IPv6 migration"? Letting IPv6 migration state factor as decision input on anything not directly related to IPv6 migration was never logical, just naively optimistic, and should be stamped out wherever encountered. If its good, use it now and Ipv6 will adopt it as well. If it isnt, why wait to find out? Joe Mel Beckman wrote:

Mike,

Thanks for that useful example. On a side note, Netflix is a thorn in all our sides :) You could put a localpref filter route to override the default for Netflix prefixes, but this impacts resilience. Since you peer with Netflix, I suspect we probably agree that Netflix’s ideas on traffic engineering are pretty one sided.

I think it’s safe to say that BGP, which has scaled amazingly well, didn’t anticipate some of the big gorilla content systems. I don’t really see, though, how injecting FIB entries helps more than other methods. And as others have pointed out, the risk of creating routing loops is significant.

Perhaps it is time to migrate to a new version of BGP. Projects like MBGP and FP-7‘s 4WARD are working on new follow-on routing models, but nothing is on the immediate horizon. I think we all thought we should finish IPv6 migration first :)

-mel via cell

...

On Jan 5, 2023, at 1:11 PM, Mike Hammett <nanog@ics-il.net> wrote:

 I hesitated to get too specific in examples because someone is going to drag the conversation into the weeds.

Let's take the the Dallas - New Orleans - Atlanta example where I have a connection from New Orleans to Dallas and a connection from New Orleans to Atlanta.

Let's say I peer with Netflix in both markets. Netflix chooses to serve me out of Atlanta, for whatever reason. Say my default route sends my traffic to Dallas. That's not where Netflix wanted it, so now I have to go from Dallas to Atlanta, whether that's my circuit or across the public Internet. Potentially, it's on MPLS and it rides back through the New Orleans router to get back to Atlanta. That's a long trip when I already had a better path, the less-than-full-fib router just didn't know about it. Given that Netflix is a sizable amount of traffic in an eyeball ISP, that's a lot of traffic to be going the wrong way. If the website for Viktor's Arctic Plunge in Siberia was hosted in Atlanta, I wouldn't give two craps that the traffic went the wrong way because A), I'll probably never go there and B) when someone does, it won't be meaningfully enough traffic to accommodate.

Someone's going to tell me to put a full-table router in New Orleans. Maybe I should. Okay, so maybe I have a POP in Ashford, Alabama. It has transport to New Orleans and Atlanta. There aren't enough grains of sugar in Ashford, Alabama to justify a current-generation, full table router. Now I'm even closer to Atlanta, but default may point to New Orleans.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentComputingSolutionsDeKalb><https://www.linkedin.com/company/intelligent-computing-solutions><https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><https://www.linkedin.com/company/midwest-internet-exchange><https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------------------------------------------------ *From: *"Mel Beckman" <mel@beckman.org> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Joe Maimon" <jmaimon@jmaimon.com>, "NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 2:54:27 PM *Subject: *Re: SDN Internet Router (sir)

Mike,

I’m not sure I understand what you mean by “suboptimal“ routing. Even though the Internet uses AS path length for routing, many of those path lengths are bogus, and don’t really represent any kind of path performance value. For example, a single AS might hide many hops in an MPLS network as a single hop, obscuring asymmetric routing and other uglies. Prepending also occurs when destinations are trying to enforce their own engineering policies, which often conflict with yours or mine.

So what do you mean by “suboptimal“? Are you thinking that the “best” path in BGP tables actually meant you were getting a performance benefit? Because that’s definitely not the case in today’s Internet. Were were you thinking that you would be going along less congested paths? That’s really at the mercy of the traffic engineering of backbone providers over which we have no control.

I generally populate local router FIBs to merel choose an exit point for purposes of load balancing, and nothing more.

-mel

On Jan 5, 2023, at 12:38 PM, Mike Hammett <nanog@ics-il.net> wrote:

 I guess I wasn't around for those days.

As far as running out, again, assuming the tooling works correctly, I'd think to target fewer routes than you could hold. Maybe 1k routes is all one would need to get a significant percent of the traffic. A lot of room to mess up if you can hold 100k, 500k routes.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentComputingSolutionsDeKalb><https://www.linkedin.com/company/intelligent-computing-solutions><https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><https://www.linkedin.com/company/midwest-internet-exchange><https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------------------------------------------------ *From: *"Joe Maimon" <jmaimon@jmaimon.com> *To: *"Mike Hammett" <nanog@ics-il.net>, "Christopher Morrow" <morrowc.lists@gmail.com> *Cc: *"NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 2:30:40 PM *Subject: *Re: SDN Internet Router (sir)

Mike Hammett wrote: > I'm not concerned with which technology or buzzword gets the job done, > only that the job is done. > > > > Looking briefly at the couple of things out there, they're evaluating > the top X prefixes in terms of traffic reported by s-flow, where X is > the number I define, and those get pushed into the FIB. One > recalculates every hour, one does so more quickly. How much is > appropriate? I'm not sure. I can't imagine it would *NEED* to be done > all of that often, given the traffic/prefix density an eyeball network > will have. Default routes carry the rest. Default routes could be > handled outside of this process, such that if this process fails, you > just get some sub-optimal routing until repaired. Maybe it doesn't > filter properly and sends a bunch of routes. Then just have a prefix > limit set on the box. Maybe it sends the wrong prefixes. No harm, no > foul. If you're routing sub-optimally internally, when it does hit a > real router with a full FIB, it gets handled appropriately.

Unless it loops.

The rest sounds nice. But flow caching got a bad rap back in the early worm days. But thats because the situation was a little worse back then. Cache the wrong routes or run out of cache, router dies. So long as thats not the case automating optimization is an extremely valuable goal.

> > > I would just be looking for solutions that influence what's in the FIB > and let the rest of the router work as the rest of the router would.

The problem comes when the router wont work at all without the FIB routes, like in the olden days. > > > > ----- > Mike Hammett > Intelligent Computing Solutions <http://www.ics-il.com/> > <https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentComputingSolutionsDeKalb><https://www.linkedin.com/company/intelligent-computing-solutions><https://twitter.com/ICSIL> > Midwest Internet Exchange <http://www.midwest-ix.com/> > <https://www.facebook.com/mdwestix><https://www.linkedin.com/company/midwest-internet-exchange><https://twitter.com/mdwestix> > The Brothers WISP <http://www.thebrotherswisp.com/> > <https://www.facebook.com/thebrotherswisp><https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> > ------------------------------------------------------------------------ > *From: *"Christopher Morrow" <morrowc.lists@gmail.com> > *To: *"Mike Hammett" <nanog@ics-il.net> > *Cc: *"Tom Beecher" <beecher@beecher.cc>, "NANOG" <nanog@nanog.org> > *Sent: *Thursday, January 5, 2023 12:27:08 PM > *Subject: *Re: SDN Internet Router (sir) > > > > On Thu, Jan 5, 2023 at 11:18 AM Mike Hammett <nanog@ics-il.net > <mailto:nanog@ics-il.net>> wrote: > > Initially, my thought was to use community filtering to push just > IXes, customers, and defaults throughout the network, but that's > obviously still sub-optimal. > > I'd be surprised if a last mile network had a ton of traffic going > to any more than a few hundred prefixes. > > > I think in a low-fib box at the edge of your network your choices are: > "the easy choice, get default, follow that" > > "send some limited set of prefixes to the device, and default, so > you MAY choose better for the initial hop away" > > you certainly can do the second with communities, or route-filters > (prefix-list) on the senders, or.... > you can choose what prefixes make the cut (get the community(ies)) > based on traffic volumes or expected destination locality: > "do not go east to go west!" > > these things will introduce toil and SOME suboptimal routing in some > instances... perhaps it's better than per flow choosing left/right > though and the support calls related to that choice. > > In your NOLA / DFW / ATL example it's totally possible that the > networks in question do something like: > "low fib box in tier-2 city (NOLA), dfz capable/core devices in > tier-1 city (DFW/ATL), and send default from left/right to NOLA" > > Could they send more prefixes than default? sure... do they want to > deal with the toil that induces? (probably not says your example). > > SDN isn't really an answer to this, though.. I don't think. Unless you > envision that to lower the toil ? >

Thanks for this example. It sounds like you are describing egress peer engineering, but kinda in reverse. In 'traditional' EPE, the routers have all the routes, and you are using the external controller to perform the performance tests that matter to you, and signal the network where to take the traffic based on those tests. It seems like you want to do the same thing , but instead of having the controller signal the network where to carry bits, you want the controller to signal the networks what routes are present, and direct the bits that way. Do I have this right? On Thu, Jan 5, 2023 at 4:12 PM Mike Hammett <nanog@ics-il.net> wrote:

I hesitated to get too specific in examples because someone is going to drag the conversation into the weeds.

Let's take the the Dallas - New Orleans - Atlanta example where I have a connection from New Orleans to Dallas and a connection from New Orleans to Atlanta.

Let's say I peer with Netflix in both markets. Netflix chooses to serve me out of Atlanta, for whatever reason. Say my default route sends my traffic to Dallas. That's not where Netflix wanted it, so now I have to go from Dallas to Atlanta, whether that's my circuit or across the public Internet. Potentially, it's on MPLS and it rides back through the New Orleans router to get back to Atlanta. That's a long trip when I already had a better path, the less-than-full-fib router just didn't know about it. Given that Netflix is a sizable amount of traffic in an eyeball ISP, that's a lot of traffic to be going the wrong way. If the website for Viktor's Arctic Plunge in Siberia was hosted in Atlanta, I wouldn't give two craps that the traffic went the wrong way because A), I'll probably never go there and B) when someone does, it won't be meaningfully enough traffic to accommodate.

Someone's going to tell me to put a full-table router in New Orleans. Maybe I should. Okay, so maybe I have a POP in Ashford, Alabama. It has transport to New Orleans and Atlanta. There aren't enough grains of sugar in Ashford, Alabama to justify a current-generation, full table router. Now I'm even closer to Atlanta, but default may point to New Orleans.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------ *From: *"Mel Beckman" <mel@beckman.org> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Joe Maimon" <jmaimon@jmaimon.com>, "NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 2:54:27 PM *Subject: *Re: SDN Internet Router (sir)

Mike,

I’m not sure I understand what you mean by “suboptimal“ routing. Even though the Internet uses AS path length for routing, many of those path lengths are bogus, and don’t really represent any kind of path performance value. For example, a single AS might hide many hops in an MPLS network as a single hop, obscuring asymmetric routing and other uglies. Prepending also occurs when destinations are trying to enforce their own engineering policies, which often conflict with yours or mine.

So what do you mean by “suboptimal“? Are you thinking that the “best” path in BGP tables actually meant you were getting a performance benefit? Because that’s definitely not the case in today’s Internet. Were were you thinking that you would be going along less congested paths? That’s really at the mercy of the traffic engineering of backbone providers over which we have no control.

I generally populate local router FIBs to merel choose an exit point for purposes of load balancing, and nothing more.

-mel

On Jan 5, 2023, at 12:38 PM, Mike Hammett <nanog@ics-il.net> wrote:

 I guess I wasn't around for those days.

As far as running out, again, assuming the tooling works correctly, I'd think to target fewer routes than you could hold. Maybe 1k routes is all one would need to get a significant percent of the traffic. A lot of room to mess up if you can hold 100k, 500k routes.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------ *From: *"Joe Maimon" <jmaimon@jmaimon.com> *To: *"Mike Hammett" <nanog@ics-il.net>, "Christopher Morrow" < morrowc.lists@gmail.com> *Cc: *"NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 2:30:40 PM *Subject: *Re: SDN Internet Router (sir)

Mike Hammett wrote:

...

I'm not concerned with which technology or buzzword gets the job done, only that the job is done.

Looking briefly at the couple of things out there, they're evaluating the top X prefixes in terms of traffic reported by s-flow, where X is the number I define, and those get pushed into the FIB. One recalculates every hour, one does so more quickly. How much is appropriate? I'm not sure. I can't imagine it would *NEED* to be done all of that often, given the traffic/prefix density an eyeball network will have. Default routes carry the rest. Default routes could be handled outside of this process, such that if this process fails, you just get some sub-optimal routing until repaired. Maybe it doesn't filter properly and sends a bunch of routes. Then just have a prefix limit set on the box. Maybe it sends the wrong prefixes. No harm, no foul. If you're routing sub-optimally internally, when it does hit a real router with a full FIB, it gets handled appropriately.

Unless it loops.

The rest sounds nice. But flow caching got a bad rap back in the early worm days. But thats because the situation was a little worse back then. Cache the wrong routes or run out of cache, router dies. So long as thats not the case automating optimization is an extremely valuable goal.

...

I would just be looking for solutions that influence what's in the FIB and let the rest of the router work as the rest of the router would.

The problem comes when the router wont work at all without the FIB routes, like in the olden days.

...

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><;

https://plus.google.com/+IntelligentComputingSolutionsDeKalb><; https://www.linkedin.com/company/intelligent-computing-solutions><; https://twitter.com/ICSIL>

...

Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><; https://www.linkedin.com/company/midwest-internet-exchange><; https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><; https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------------------------------------------------ *From: *"Christopher Morrow" <morrowc.lists@gmail.com> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Tom Beecher" <beecher@beecher.cc>, "NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 12:27:08 PM *Subject: *Re: SDN Internet Router (sir)

On Thu, Jan 5, 2023 at 11:18 AM Mike Hammett <nanog@ics-il.net <mailto:nanog@ics-il.net>> wrote:

Initially, my thought was to use community filtering to push just IXes, customers, and defaults throughout the network, but that's obviously still sub-optimal.

I'd be surprised if a last mile network had a ton of traffic going to any more than a few hundred prefixes.

I think in a low-fib box at the edge of your network your choices are: "the easy choice, get default, follow that"

"send some limited set of prefixes to the device, and default, so you MAY choose better for the initial hop away"

you certainly can do the second with communities, or route-filters (prefix-list) on the senders, or.... you can choose what prefixes make the cut (get the community(ies)) based on traffic volumes or expected destination locality: "do not go east to go west!"

these things will introduce toil and SOME suboptimal routing in some instances... perhaps it's better than per flow choosing left/right though and the support calls related to that choice.

In your NOLA / DFW / ATL example it's totally possible that the networks in question do something like: "low fib box in tier-2 city (NOLA), dfz capable/core devices in tier-1 city (DFW/ATL), and send default from left/right to NOLA"

Could they send more prefixes than default? sure... do they want to deal with the toil that induces? (probably not says your example).

SDN isn't really an answer to this, though.. I don't think. Unless you envision that to lower the toil ?

Gotcha. Setup a Quagga/Bird box. Do your top talker analysis , use that box to inject the routes you deem important with communities. On your routers , create policy structure to only take a default plus those communities. Obviously lots of devils in the details of the implementation , but something like that is all you need to do. On Fri, Jan 6, 2023 at 10:29 Mike Hammett <nanog@ics-il.net> wrote:

Maybe?

I don't need any additional performance tests, though. Just watching which prefixes are the top talkers and leaving the rest to default.

I'm not looking at this to do what a BGP optimizier would do and find the best tested path to the top talkers and then massage BGP to get it routed that way. Determine the top talkers, then let BGP do its thing for those top talkers.

I don't want to manually say X traffic from Y POP manually goes here, but I don't want to just leave it to default routing either. Something in the middle.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------ *From: *"Tom Beecher" <beecher@beecher.cc> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Mel Beckman" <mel@beckman.org>, "NANOG" <nanog@nanog.org> *Sent: *Friday, January 6, 2023 9:16:19 AM

*Subject: *Re: SDN Internet Router (sir)

Thanks for this example.

It sounds like you are describing egress peer engineering, but kinda in reverse.

In 'traditional' EPE, the routers have all the routes, and you are using the external controller to perform the performance tests that matter to you, and signal the network where to take the traffic based on those tests.

It seems like you want to do the same thing , but instead of having the controller signal the network where to carry bits, you want the controller to signal the networks what routes are present, and direct the bits that way.

Do I have this right?

On Thu, Jan 5, 2023 at 4:12 PM Mike Hammett <nanog@ics-il.net> wrote:

...

I hesitated to get too specific in examples because someone is going to drag the conversation into the weeds.

Let's take the the Dallas - New Orleans - Atlanta example where I have a connection from New Orleans to Dallas and a connection from New Orleans to Atlanta.

Let's say I peer with Netflix in both markets. Netflix chooses to serve me out of Atlanta, for whatever reason. Say my default route sends my traffic to Dallas. That's not where Netflix wanted it, so now I have to go from Dallas to Atlanta, whether that's my circuit or across the public Internet. Potentially, it's on MPLS and it rides back through the New Orleans router to get back to Atlanta. That's a long trip when I already had a better path, the less-than-full-fib router just didn't know about it. Given that Netflix is a sizable amount of traffic in an eyeball ISP, that's a lot of traffic to be going the wrong way. If the website for Viktor's Arctic Plunge in Siberia was hosted in Atlanta, I wouldn't give two craps that the traffic went the wrong way because A), I'll probably never go there and B) when someone does, it won't be meaningfully enough traffic to accommodate.

Someone's going to tell me to put a full-table router in New Orleans. Maybe I should. Okay, so maybe I have a POP in Ashford, Alabama. It has transport to New Orleans and Atlanta. There aren't enough grains of sugar in Ashford, Alabama to justify a current-generation, full table router. Now I'm even closer to Atlanta, but default may point to New Orleans.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------ *From: *"Mel Beckman" <mel@beckman.org> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Joe Maimon" <jmaimon@jmaimon.com>, "NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 2:54:27 PM *Subject: *Re: SDN Internet Router (sir)

Mike,

I’m not sure I understand what you mean by “suboptimal“ routing. Even though the Internet uses AS path length for routing, many of those path lengths are bogus, and don’t really represent any kind of path performance value. For example, a single AS might hide many hops in an MPLS network as a single hop, obscuring asymmetric routing and other uglies. Prepending also occurs when destinations are trying to enforce their own engineering policies, which often conflict with yours or mine.

So what do you mean by “suboptimal“? Are you thinking that the “best” path in BGP tables actually meant you were getting a performance benefit? Because that’s definitely not the case in today’s Internet. Were were you thinking that you would be going along less congested paths? That’s really at the mercy of the traffic engineering of backbone providers over which we have no control.

I generally populate local router FIBs to merel choose an exit point for purposes of load balancing, and nothing more.

-mel

On Jan 5, 2023, at 12:38 PM, Mike Hammett <nanog@ics-il.net> wrote:

 I guess I wasn't around for those days.

As far as running out, again, assuming the tooling works correctly, I'd think to target fewer routes than you could hold. Maybe 1k routes is all one would need to get a significant percent of the traffic. A lot of room to mess up if you can hold 100k, 500k routes.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------ *From: *"Joe Maimon" <jmaimon@jmaimon.com> *To: *"Mike Hammett" <nanog@ics-il.net>, "Christopher Morrow" < morrowc.lists@gmail.com> *Cc: *"NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 2:30:40 PM *Subject: *Re: SDN Internet Router (sir)

Mike Hammett wrote:

...

I'm not concerned with which technology or buzzword gets the job done, only that the job is done.

Looking briefly at the couple of things out there, they're evaluating the top X prefixes in terms of traffic reported by s-flow, where X is the number I define, and those get pushed into the FIB. One recalculates every hour, one does so more quickly. How much is appropriate? I'm not sure. I can't imagine it would *NEED* to be done all of that often, given the traffic/prefix density an eyeball network will have. Default routes carry the rest. Default routes could be handled outside of this process, such that if this process fails, you just get some sub-optimal routing until repaired. Maybe it doesn't filter properly and sends a bunch of routes. Then just have a prefix limit set on the box. Maybe it sends the wrong prefixes. No harm, no foul. If you're routing sub-optimally internally, when it does hit a real router with a full FIB, it gets handled appropriately.

Unless it loops.

The rest sounds nice. But flow caching got a bad rap back in the early worm days. But thats because the situation was a little worse back then. Cache the wrong routes or run out of cache, router dies. So long as thats not the case automating optimization is an extremely valuable goal.

...

I would just be looking for solutions that influence what's in the FIB and let the rest of the router work as the rest of the router would.

The problem comes when the router wont work at all without the FIB routes, like in the olden days.

...

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><;

https://plus.google.com/+IntelligentComputingSolutionsDeKalb><; https://www.linkedin.com/company/intelligent-computing-solutions><; https://twitter.com/ICSIL>

...

Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><; https://www.linkedin.com/company/midwest-internet-exchange><; https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><; https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------------------------------------------------ *From: *"Christopher Morrow" <morrowc.lists@gmail.com> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Tom Beecher" <beecher@beecher.cc>, "NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 12:27:08 PM *Subject: *Re: SDN Internet Router (sir)

On Thu, Jan 5, 2023 at 11:18 AM Mike Hammett <nanog@ics-il.net <mailto:nanog@ics-il.net>> wrote:

Initially, my thought was to use community filtering to push just IXes, customers, and defaults throughout the network, but that's obviously still sub-optimal.

I'd be surprised if a last mile network had a ton of traffic going to any more than a few hundred prefixes.

I think in a low-fib box at the edge of your network your choices are: "the easy choice, get default, follow that"

"send some limited set of prefixes to the device, and default, so you MAY choose better for the initial hop away"

you certainly can do the second with communities, or route-filters (prefix-list) on the senders, or.... you can choose what prefixes make the cut (get the community(ies)) based on traffic volumes or expected destination locality: "do not go east to go west!"

these things will introduce toil and SOME suboptimal routing in some instances... perhaps it's better than per flow choosing left/right though and the support calls related to that choice.

In your NOLA / DFW / ATL example it's totally possible that the networks in question do something like: "low fib box in tier-2 city (NOLA), dfz capable/core devices in tier-1 city (DFW/ATL), and send default from left/right to NOLA"

Could they send more prefixes than default? sure... do they want to deal with the toil that induces? (probably not says your example).

SDN isn't really an answer to this, though.. I don't think. Unless you envision that to lower the toil ?

What I originally linked to (and another link or two contributed since then) seem to be people that already built that solution.

What's been shared isn't the same as what I described. faucet / sir are doing the decision part and the signaling part together. I am saying separate them. BGP doesn't know how to make the *decision* you want, but it does know how to process *signals* that you send it. On Fri, Jan 6, 2023 at 10:58 AM Mike Hammett <nanog@ics-il.net> wrote:

Right.

Only I'm not the guy to build that solution.

What I originally linked to (and another link or two contributed since then) seem to be people that already built that solution.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------ *From: *"Tom Beecher" <beecher@beecher.cc> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Mel Beckman" <mel@beckman.org>, "NANOG" <nanog@nanog.org> *Sent: *Friday, January 6, 2023 9:51:43 AM *Subject: *Re: SDN Internet Router (sir)

Gotcha.

Setup a Quagga/Bird box. Do your top talker analysis , use that box to inject the routes you deem important with communities. On your routers , create policy structure to only take a default plus those communities.

Obviously lots of devils in the details of the implementation , but something like that is all you need to do.

On Fri, Jan 6, 2023 at 10:29 Mike Hammett <nanog@ics-il.net> wrote:

...

Maybe?

I don't need any additional performance tests, though. Just watching which prefixes are the top talkers and leaving the rest to default.

I'm not looking at this to do what a BGP optimizier would do and find the best tested path to the top talkers and then massage BGP to get it routed that way. Determine the top talkers, then let BGP do its thing for those top talkers.

I don't want to manually say X traffic from Y POP manually goes here, but I don't want to just leave it to default routing either. Something in the middle.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------ *From: *"Tom Beecher" <beecher@beecher.cc> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Mel Beckman" <mel@beckman.org>, "NANOG" <nanog@nanog.org> *Sent: *Friday, January 6, 2023 9:16:19 AM

*Subject: *Re: SDN Internet Router (sir)

Thanks for this example.

It sounds like you are describing egress peer engineering, but kinda in reverse.

In 'traditional' EPE, the routers have all the routes, and you are using the external controller to perform the performance tests that matter to you, and signal the network where to take the traffic based on those tests.

It seems like you want to do the same thing , but instead of having the controller signal the network where to carry bits, you want the controller to signal the networks what routes are present, and direct the bits that way.

Do I have this right?

On Thu, Jan 5, 2023 at 4:12 PM Mike Hammett <nanog@ics-il.net> wrote:

...

I hesitated to get too specific in examples because someone is going to drag the conversation into the weeds.

Let's take the the Dallas - New Orleans - Atlanta example where I have a connection from New Orleans to Dallas and a connection from New Orleans to Atlanta.

Let's say I peer with Netflix in both markets. Netflix chooses to serve me out of Atlanta, for whatever reason. Say my default route sends my traffic to Dallas. That's not where Netflix wanted it, so now I have to go from Dallas to Atlanta, whether that's my circuit or across the public Internet. Potentially, it's on MPLS and it rides back through the New Orleans router to get back to Atlanta. That's a long trip when I already had a better path, the less-than-full-fib router just didn't know about it. Given that Netflix is a sizable amount of traffic in an eyeball ISP, that's a lot of traffic to be going the wrong way. If the website for Viktor's Arctic Plunge in Siberia was hosted in Atlanta, I wouldn't give two craps that the traffic went the wrong way because A), I'll probably never go there and B) when someone does, it won't be meaningfully enough traffic to accommodate.

Someone's going to tell me to put a full-table router in New Orleans. Maybe I should. Okay, so maybe I have a POP in Ashford, Alabama. It has transport to New Orleans and Atlanta. There aren't enough grains of sugar in Ashford, Alabama to justify a current-generation, full table router. Now I'm even closer to Atlanta, but default may point to New Orleans.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------ *From: *"Mel Beckman" <mel@beckman.org> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Joe Maimon" <jmaimon@jmaimon.com>, "NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 2:54:27 PM *Subject: *Re: SDN Internet Router (sir)

Mike,

I’m not sure I understand what you mean by “suboptimal“ routing. Even though the Internet uses AS path length for routing, many of those path lengths are bogus, and don’t really represent any kind of path performance value. For example, a single AS might hide many hops in an MPLS network as a single hop, obscuring asymmetric routing and other uglies. Prepending also occurs when destinations are trying to enforce their own engineering policies, which often conflict with yours or mine.

So what do you mean by “suboptimal“? Are you thinking that the “best” path in BGP tables actually meant you were getting a performance benefit? Because that’s definitely not the case in today’s Internet. Were were you thinking that you would be going along less congested paths? That’s really at the mercy of the traffic engineering of backbone providers over which we have no control.

I generally populate local router FIBs to merel choose an exit point for purposes of load balancing, and nothing more.

-mel

On Jan 5, 2023, at 12:38 PM, Mike Hammett <nanog@ics-il.net> wrote:

 I guess I wasn't around for those days.

As far as running out, again, assuming the tooling works correctly, I'd think to target fewer routes than you could hold. Maybe 1k routes is all one would need to get a significant percent of the traffic. A lot of room to mess up if you can hold 100k, 500k routes.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------ *From: *"Joe Maimon" <jmaimon@jmaimon.com> *To: *"Mike Hammett" <nanog@ics-il.net>, "Christopher Morrow" < morrowc.lists@gmail.com> *Cc: *"NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 2:30:40 PM *Subject: *Re: SDN Internet Router (sir)

Mike Hammett wrote:

...

I'm not concerned with which technology or buzzword gets the job done, only that the job is done.

Looking briefly at the couple of things out there, they're evaluating the top X prefixes in terms of traffic reported by s-flow, where X is the number I define, and those get pushed into the FIB. One recalculates every hour, one does so more quickly. How much is appropriate? I'm not sure. I can't imagine it would *NEED* to be done all of that often, given the traffic/prefix density an eyeball network will have. Default routes carry the rest. Default routes could be handled outside of this process, such that if this process fails, you just get some sub-optimal routing until repaired. Maybe it doesn't filter properly and sends a bunch of routes. Then just have a prefix limit set on the box. Maybe it sends the wrong prefixes. No harm, no foul. If you're routing sub-optimally internally, when it does hit a real router with a full FIB, it gets handled appropriately.

Unless it loops.

The rest sounds nice. But flow caching got a bad rap back in the early worm days. But thats because the situation was a little worse back then. Cache the wrong routes or run out of cache, router dies. So long as thats not the case automating optimization is an extremely valuable goal.

...

I would just be looking for solutions that influence what's in the FIB and let the rest of the router work as the rest of the router would.

The problem comes when the router wont work at all without the FIB routes, like in the olden days.

...

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><;

https://plus.google.com/+IntelligentComputingSolutionsDeKalb><; https://www.linkedin.com/company/intelligent-computing-solutions><; https://twitter.com/ICSIL>

...

Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><; https://www.linkedin.com/company/midwest-internet-exchange><; https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><; https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg>

------------------------------------------------------------------------

...

*From: *"Christopher Morrow" <morrowc.lists@gmail.com> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Tom Beecher" <beecher@beecher.cc>, "NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 12:27:08 PM *Subject: *Re: SDN Internet Router (sir)

On Thu, Jan 5, 2023 at 11:18 AM Mike Hammett <nanog@ics-il.net <mailto:nanog@ics-il.net>> wrote:

Initially, my thought was to use community filtering to push just IXes, customers, and defaults throughout the network, but that's obviously still sub-optimal.

I'd be surprised if a last mile network had a ton of traffic going to any more than a few hundred prefixes.

I think in a low-fib box at the edge of your network your choices are: "the easy choice, get default, follow that"

"send some limited set of prefixes to the device, and default, so you MAY choose better for the initial hop away"

you certainly can do the second with communities, or route-filters (prefix-list) on the senders, or.... you can choose what prefixes make the cut (get the community(ies)) based on traffic volumes or expected destination locality: "do not go east to go west!"

these things will introduce toil and SOME suboptimal routing in some instances... perhaps it's better than per flow choosing left/right though and the support calls related to that choice.

In your NOLA / DFW / ATL example it's totally possible that the networks in question do something like: "low fib box in tier-2 city (NOLA), dfz capable/core devices in tier-1 city (DFW/ATL), and send default from left/right to NOLA"

Could they send more prefixes than default? sure... do they want to deal with the toil that induces? (probably not says your example).

SDN isn't really an answer to this, though.. I don't think. Unless you envision that to lower the toil ?

This is not a green grass problem space. https://www.cisco.com/c/en/us/products/ios-nx-os-software/performance-routin... And you could probably envision how you could create your own internal scheme of route reflectors/servers, community tags, probers and updaters to achieve something similar. Most likely Mike is referring to the sub-optimal result where a large percentage of a router's traffic is taking extra internal hops or worse, maybe even egressing from the AS into a less than optimal path, not because the AS does not have the correct route for the most likely as perceived by BGP optimal path, but that the traffic handling device was not able to be configured to accept any such routes, because doing such statically is not likely to achieve the results and more likely to result in crashed routers one unexpected fine morning. Nanogers pointed me at this some time back, I think its germaine https://blog.google/products/google-cloud/making-google-cloud-faster-more-av... RIB/FIB static configuration limitation tip: Apply the same logic on all similar capacity devices to cut down on the RIBFIB, because thats the best way to minimize loops. And a guaranteed loop free path for the default route. Policy or tag tunnel or whatever. Joe Mel Beckman wrote:

Mike,

I’m not sure I understand what you mean by “suboptimal“ routing. Even though the Internet uses AS path length for routing, many of those path lengths are bogus, and don’t really represent any kind of path performance value. For example, a single AS might hide many hops in an MPLS network as a single hop, obscuring asymmetric routing and other uglies. Prepending also occurs when destinations are trying to enforce their own engineering policies, which often conflict with yours or mine.

So what do you mean by “suboptimal“? Are you thinking that the “best” path in BGP tables actually meant you were getting a performance benefit? Because that’s definitely not the case in today’s Internet. Were were you thinking that you would be going along less congested paths? That’s really at the mercy of the traffic engineering of backbone providers over which we have no control.

I generally populate local router FIBs to merel choose an exit point for purposes of load balancing, and nothing more.

-mel

...

On Jan 5, 2023, at 12:38 PM, Mike Hammett <nanog@ics-il.net> wrote:

 I guess I wasn't around for those days.

As far as running out, again, assuming the tooling works correctly, I'd think to target fewer routes than you could hold. Maybe 1k routes is all one would need to get a significant percent of the traffic. A lot of room to mess up if you can hold 100k, 500k routes.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentComputingSolutionsDeKalb><https://www.linkedin.com/company/intelligent-computing-solutions><https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><https://www.linkedin.com/company/midwest-internet-exchange><https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------------------------------------------------ *From: *"Joe Maimon" <jmaimon@jmaimon.com> *To: *"Mike Hammett" <nanog@ics-il.net>, "Christopher Morrow" <morrowc.lists@gmail.com> *Cc: *"NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 2:30:40 PM *Subject: *Re: SDN Internet Router (sir)

Mike Hammett wrote:

...

I'm not concerned with which technology or buzzword gets the job done, only that the job is done.

Looking briefly at the couple of things out there, they're evaluating the top X prefixes in terms of traffic reported by s-flow, where X is the number I define, and those get pushed into the FIB. One recalculates every hour, one does so more quickly. How much is appropriate? I'm not sure. I can't imagine it would *NEED* to be done all of that often, given the traffic/prefix density an eyeball network will have. Default routes carry the rest. Default routes could be handled outside of this process, such that if this process fails, you just get some sub-optimal routing until repaired. Maybe it doesn't filter properly and sends a bunch of routes. Then just have a prefix limit set on the box. Maybe it sends the wrong prefixes. No harm, no foul. If you're routing sub-optimally internally, when it does hit a real router with a full FIB, it gets handled appropriately.

Unless it loops.

The rest sounds nice. But flow caching got a bad rap back in the early worm days. But thats because the situation was a little worse back then. Cache the wrong routes or run out of cache, router dies. So long as thats not the case automating optimization is an extremely valuable goal.

...

I would just be looking for solutions that influence what's in the FIB and let the rest of the router work as the rest of the router would.

The problem comes when the router wont work at all without the FIB routes, like in the olden days.

...

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/>

<https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentComputingSolutionsDeKalb><https://www.linkedin.com/company/intelligent-computing-solutions><https://twitter.com/ICSIL>

...

Midwest Internet Exchange <http://www.midwest-ix.com/>

<https://www.facebook.com/mdwestix><https://www.linkedin.com/company/midwest-internet-exchange><https://twitter.com/mdwestix>

...

The Brothers WISP <http://www.thebrotherswisp.com/>

<https://www.facebook.com/thebrotherswisp><https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg>

...

------------------------------------------------------------------------

...

*From: *"Christopher Morrow" <morrowc.lists@gmail.com> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Tom Beecher" <beecher@beecher.cc>, "NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 12:27:08 PM *Subject: *Re: SDN Internet Router (sir)

On Thu, Jan 5, 2023 at 11:18 AM Mike Hammett <nanog@ics-il.net <mailto:nanog@ics-il.net>> wrote:

Initially, my thought was to use community filtering to push just IXes, customers, and defaults throughout the network, but that's obviously still sub-optimal.

I'd be surprised if a last mile network had a ton of traffic going to any more than a few hundred prefixes.

I think in a low-fib box at the edge of your network your choices are: "the easy choice, get default, follow that"

"send some limited set of prefixes to the device, and default, so you MAY choose better for the initial hop away"

you certainly can do the second with communities, or route-filters (prefix-list) on the senders, or.... you can choose what prefixes make the cut (get the community(ies)) based on traffic volumes or expected destination locality: "do not go east to go west!"

these things will introduce toil and SOME suboptimal routing in some instances... perhaps it's better than per flow choosing left/right though and the support calls related to that choice.

In your NOLA / DFW / ATL example it's totally possible that the networks in question do something like: "low fib box in tier-2 city (NOLA), dfz capable/core devices in tier-1 city (DFW/ATL), and send default from left/right to NOLA"

Could they send more prefixes than default? sure... do they want to deal with the toil that induces? (probably not says your example).

SDN isn't really an answer to this, though.. I don't think. Unless you envision that to lower the toil ?

Very true. https://www.cidr-report.org/cgi-bin/plota?file=%2fvar%2fdata%2fbgp%2fas2.0%2fbgp%2dactive%2etxt&descr=Active%20BGP%20entries%20%28FIB%29&ylabel=Active%20BGP%20entries%20%28FIB%29&with=step "big enough" equipment from not that long ago couldn't carry a full table today (or tomorrow). ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP ----- Original Message ----- From: "Joe Maimon" <jmaimon@jmaimon.com> To: "Mike Hammett" <nanog@ics-il.net>, "Tom Beecher" <beecher@beecher.cc> Cc: "NANOG" <nanog@nanog.org> Sent: Thursday, January 5, 2023 2:22:22 PM Subject: Re: SDN Internet Router (sir) Lots of 1M tcam fib limits in older gear....... So yeah, its the same problem, bigger numbers and still not solved in any sort of non-painful or expensive way. I think Ill explore the google path and paper on it again. Joe Mike Hammett wrote:

Then please bless the world with the right way.

You acknowledge that not every router in a network needs to be fully DFZ capable, but then crap on my desire to have more than a default route in one.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentComputingSolutionsDeKalb><https://www.linkedin.com/company/intelligent-computing-solutions><https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><https://www.linkedin.com/company/midwest-internet-exchange><https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------------------------------------------------ *From: *"Tom Beecher" <beecher@beecher.cc> *To: *"Mike Hammett" <nanog@ics-il.net> *Cc: *"Mel Beckman" <mel@beckman.org>, "NANOG" <nanog@nanog.org> *Sent: *Thursday, January 5, 2023 9:55:38 AM *Subject: *Re: SDN Internet Router (sir)

"The right tool for the job" gets into a religious argument in assuming that one's way to do the job is the only reasonable way to do the job

I disagree that it's religious. I completely agree there are locations in networks that having full DFZ capable routers doesn't make technical or economic sense. But there have long been different products for those different use cases.

To perhaps explain my viewpoint better,(and perhaps I didn't properly comprehend the problem you're aiming to solve) :

If you are trying to use SDN stuff to shuffle routes on and off a box because you have the wrong sized routers in place, then I would argue you're doing it wrong.

If you are trying to use SDN stuff to (as Christopher mentioned) make decisions that are not strictly LPM, and the equipment you have cannot do that, then that's different and entirely reasonable.

If the second use case is more of what you were asking, then I apologize for misunderstanding.

On Thu, Jan 5, 2023 at 9:57 AM Mike Hammett <nanog@ics-il.net <mailto:nanog@ics-il.net>> wrote:

"The right tool for the job" gets into a religious argument in assuming that one's way to do the job is the only reasonable way to do the job.

Large networks historically have a very poor (IMO) model of gigantic iron in a few locations, which results in sub-optimal routing for the rest of their network between those large POPs. I've heard time and time again that someone buying service from a major network in say New Orleans has a first hop of Dallas or Atlanta. I agree that full-route capable routers need to be in the large, central locations, but it isn't cost effective to have them at every POP, especially if you're a last-mile provider.

I'd go into more examples of where it doesn't make sense to have full-route routers everywhere, but I'm afraid that the Internet would then focus on the examples instead of the core idea of intelligently putting routes into the FIBs of low-FIB routers throughout my network.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentComputingSolutionsDeKalb><https://www.linkedin.com/company/intelligent-computing-solutions><https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><https://www.linkedin.com/company/midwest-internet-exchange><https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------------------------------------------------ *From: *"Tom Beecher" <beecher@beecher.cc <mailto:beecher@beecher.cc>> *To: *"Mike Hammett" <nanog@ics-il.net <mailto:nanog@ics-il.net>> *Cc: *"Mel Beckman" <mel@beckman.org <mailto:mel@beckman.org>>, "NANOG" <nanog@nanog.org <mailto:nanog@nanog.org>> *Sent: *Wednesday, January 4, 2023 7:36:58 AM *Subject: *Re: SDN Internet Router (sir)

Disagree that it’s a line in the sand. It’s use the right tool for the job.

If a device is low FIB, it’s that way for a reason. There are plenty of ways to massage that with policy and software, depending on capabilities , but at the end of the day, trying to sort 10 pounds of shit to store in a 5 pound bag is eventually going to end up the same way.

On Tue, Jan 3, 2023 at 13:18 Mike Hammett <nanog@ics-il.net <mailto:nanog@ics-il.net>> wrote:

There are likely more networks with 10 gigabit or less total external capacity than there are with more.

Creating imaginary lines in the sand doesn't really help anyone.

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentComputingSolutionsDeKalb><https://www.linkedin.com/company/intelligent-computing-solutions><https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><https://www.linkedin.com/company/midwest-internet-exchange><https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ------------------------------------------------------------------------ *From: *"Mel Beckman" <mel@beckman.org <mailto:mel@beckman.org>> *To: *"Mike Hammett" <nanog@ics-il.net <mailto:nanog@ics-il.net>> *Cc: *"NANOG" <nanog@nanog.org <mailto:nanog@nanog.org>> *Sent: *Tuesday, January 3, 2023 10:57:34 AM *Subject: *Re: SDN Internet Router (sir)

It’s not a problem, due to cheap, plentiful high-speed memory and rapid prefix search silicon in backbone routers. The entire Internet routing table consumes at most a few gigabytes when fully structured (and only a few hundred Mbytes stored flat). That’s less memory than your average laptop sports.

Even in the worst case scenario, where every network decides to announce only its most specific prefixes, the BGP backbone would temporarily enter an oscillating state that generates a large number of routing updates into the inter-domain routing space. In this case, BGP route damping will quickly suppress the crazies while the backbone stabilizes.

Small routers should not be taking full tables, since there is no point to them being in the default free zone. For large routers, neither memory nor CPU speed are an issue. High-speed routers operating in the default-free zone have a critical path in the forwarding decision for each packet: it needs to take less than the inter-packet arrival time for minimum-sized IP packets.

This is easy to achieve with today’s hardware. A router line card with an aggregate line rate across all of its point-to-point interfaces of 10Tbps (readily available in today’s gear) can process packets with just a handful of cycles in the FIB Ternary Content Addressable Memory (TCAM) using ASIC-assisted lookups. TCAM is the most expensive component you’re paying for in such a router. It’s not cheap, but backbone routers don’t need to be cheap. They just need to not be memory-constrained.

-mel via cell

On Jan 3, 2023, at 7:47 AM, Mike Hammett <nanog@ics-il.net <mailto:nanog@ics-il.net>> wrote:

https://github.com/dbarrosop/sir

I came across this over the weekend. Given that the project was abandoned six years ago, are there any other efforts with a similar goal (more intelligently placing routes into FIBs of low-FIB capacity devices?

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentComputingSolutionsDeKalb><https://www.linkedin.com/company/intelligent-computing-solutions><https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix><https://www.linkedin.com/company/midwest-internet-exchange><https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp><https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg>

If your BGP router supports sflow or netflow and includes ASN in those, you can use akvorado, as-stat, or elastiflow. Le mar. 3 janv. 2023 à 12:16, Peter Phaal <peter.phaal@gmail.com> a écrit :

https://github.com/sflow-rt/active-routes

Inspired by SIR, but uses Bird multi-table capability to separate RIB/FIB routes.

On Tue, Jan 3, 2023 at 7:47 AM Mike Hammett <nanog@ics-il.net> wrote:

...

https://github.com/dbarrosop/sir

I came across this over the weekend. Given that the project was abandoned six years ago, are there any other efforts with a similar goal (more intelligently placing routes into FIBs of low-FIB capacity devices?

----- Mike Hammett Intelligent Computing Solutions <http://www.ics-il.com/> <https://www.facebook.com/ICSIL> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> <https://www.linkedin.com/company/intelligent-computing-solutions> <https://twitter.com/ICSIL> Midwest Internet Exchange <http://www.midwest-ix.com/> <https://www.facebook.com/mdwestix> <https://www.linkedin.com/company/midwest-internet-exchange> <https://twitter.com/mdwestix> The Brothers WISP <http://www.thebrotherswisp.com/> <https://www.facebook.com/thebrotherswisp> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg>