No. of routers carrying full routes?
Where can I find/how can one estimate the number of routers carrying the full Internet route tables? I need to convince someone that singly-homed customer route flaps/ withdrawals should *not* propagate beyond our AS. I've found some discussion of this in the July NANOG archives, and talk about cisco floating statics, etc... and that "one-way" traffic is insignificant. I haven't upgraded to 11.1 yet, but my network is simple enough [read: not redundant enough?] that all my customers are singly-connected; in that case, statics in my border routers pointing to my customer edge-router seems to make fast install moot for now. Finally, is there a *searchable* archive of NANOG anywhere? Thanks. -- David Carmean WB6YZM DC574 <dlc@silcom.com> System/Network Administration, Silicon Beach Communications Unsolicited commercial e-mail not accepted. Violators will be LARTed.
Hi David,
Where can I find/how can one estimate the number of routers carrying the full Internet route tables?
I don't know that this information is readily available.... I'd guess there are 10 "Big" ISPs w/ an average of 200 Routers w/ full tables. I'd guess there are 100 Medium ISPs w/ an average of 7 Routers w/ full tables. I'd guess there are 25 Companies w/ an average of 3 Routers w/ full tables. (200 * 10) + ( 7 * 100) + (25 * 3) = 2775 ~= 3000 Routers
I need to convince someone that singly-homed customer route flaps/ withdrawals should *not* propagate beyond our AS. I've found some discussion of this in the July NANOG archives, and talk about cisco floating statics, etc... and that "one-way" traffic is insignificant.
Uhm, I'm not sure the concensus was that they shouldn't. I believe most everyone would agree that flaps w/in CIDR blocks should not propogate, and that people should only announce the most general network possible. But, if you've got a customer singly-homed to me, ideally, from an architecturely scalable point of view, you would do well to static them to your aggregation/POP router. However, I'm not sure a quorum agreed that single-homed customers should show up in backbone tables if their routes are/were down. There are points to be made both ways, but the BB routing tables are meant to be a snapshot of the net, and if a vector points to provider P, and customer C is not reachable there, I don't really think P should announce such....
I haven't upgraded to 11.1 yet, but my network is simple enough [read: not redundant enough?] that all my customers are singly-connected; in that case, statics in my border routers pointing to my customer edge-router seems to make fast install moot for now.
I assume you're looking forward to dampening? That would be a very Good Thing. Hopefully you're not running OSPF/EIGRP/RIP w/ a customer and redistributing, but when you start doing BGP w/ customers (even singly homed ones who migrate address space like universities and research institutions) you will have a need for dynamic routes, and it may be that static-ing them is an administrative headache, with minimal benefit to the broken^H^H^H^H^H^H limited Cisco 7xx0s....
Finally, is there a *searchable* archive of NANOG anywhere?
Our benevolent friends at Merit promise it soon... -alan
In a previous message, Alan Hannan wrote:
[ Dave wrote: ]
I need to convince someone that singly-homed customer route flaps/ withdrawals should *not* propagate beyond our AS. I've found some discussion of this in the July NANOG archives, and talk about cisco floating statics, etc... and that "one-way" traffic is insignificant.
Uhm, I'm not sure the concensus was that they shouldn't. I believe most everyone would agree that flaps w/in CIDR blocks should not propogate, and that people should only announce the most general network possible.
But, if you've got a customer singly-homed to me, ideally, from an architecturely scalable point of view, you would do well to static them to your aggregation/POP router.
However, I'm not sure a quorum agreed that single-homed customers should show up in backbone tables if their routes are/were down.
There are points to be made both ways, but the BB routing tables are meant to be a snapshot of the net, and if a vector points to provider P, and customer C is not reachable there, I don't really think P should announce such....
Well, if C is aggregated into one of my blocks, and they go away for a while, I'm gonna either blackhole it or send an Unreachable. The same as I would if their non-aggregated route is not withdrawn. CIDR/ aggregation pushes this out to the edges anyway, so I'd think that this is of far lesser consequence than thrashing the defaultless/core routers. I suppose the folks who run said routers would know more than I could at this point.... -- David Carmean WB6YZM DC574 <dlc@silcom.com> System/Network Administration, Silicon Beach Communications Unsolicited commercial e-mail not accepted. Violators will be LARTed.
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