January 2001 - NANOG - lists.nanog.org

ATT Broadband / RoadRunner Routing Failures
by Daniel Senie 24 Jan '01

24 Jan '01

The ATT Broadband / MediaOne RoadRunner network in New England appears to have major routing problems. Their recorded announcement indicates they're having connectivity problems resulting in people not being able to reach web pages. Of course the problem covers more than the web... Traces to IP addresses of places I need to reach fail within the ATT Broadband network, or within the ATT.NET space (i.e. either in net 24 or net 12). This has been going on since at least 6:30AM EST. I first noticed an inability to reach quite a few DNS servers. I can get to my colo, though. My servers in the colo appear able to see everywhere (so hopefully the reverse is also true). Looks like some very broken routing going on in ATT land. -- ----------------------------------------------------------------- Daniel Senie dts(a)senie.com Amaranth Networks Inc. http://www.amaranth.com

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Great job AT&T (re: Microsoft problems)
by Sean Donelan 24 Jan '01

24 Jan '01

Well, AT&T couldn't fix the problem, but at least their customer service people knew there was a problem and were willing to attempt contact with someone at Microsoft. Most Microsoft sites (Microsoft.com, MSN.com, Hotmail.com, etc.) are affected. The Microsoft technical team is troubleshooting this issue.

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Earthlink - nationwide problems
by Sean Donelan 23 Jan '01

23 Jan '01

Earthlink says they are experiencing a nationwide problem, but no details what the problem is.

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MAE-ATM now supports "best effort" PVCs
by Simon Lockhart 23 Jan '01

23 Jan '01

Thought this may be of interest to people. I've just received notification that Worldcom are rolling out (as of Midnight Wednesday Pacific time) a new version of Peermaker which allows you to create "best effort" PVCs at the MAE-ATM's. These are not true UBR PVCs, but rather a PVC with a commit rate of 100 cells/sec, and burst rate of your line speed. These are certainly a lot easier to work with than the old version where you had to predict how big a PVC to create for each peer! Simon

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Re: Tricky BGP into IGP Question
by Paul Donner 23 Jan '01

23 Jan '01

turn synch off. make sure bgp next-hop is propagated (1->2a->2b/4->3). do not redistribute BGP=>IGP. At 03:26 PM 1/23/01 -0800, you wrote: > > >What is the preferred way to get transit customers routing information into >your IGP so that BGP will announce the route to it's neighbors. > >1===2a===2b====3 > | > 4 > >1 is the customer, announcing to 2a, who propogates 1's route to 2b and to >4. 2b will not announce the route to 3 as it doesn't have a route in it's >routing table for 1's route. I was thinking about redistributing bgp into >my igp using a route-map based on as-path filter, but that seems somewhat >kludgy. What are you all doing to accomplish this or am I just missing >something here? > >Thanks, > >--Tim > >============================================= > Timothy M. Wolfe CCNA, NSA > Sr. Security Engineer tim(a)ignw.com > InfoGroup Northwest 541.485.0957 x108 >============================================= > Paul G. Donner Consulting Engineering Office of the CTO Internet Architecture ciscoSystems, Inc.

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Re: Broadwing Fiber cut, El Paso, TX
by Matt Zimmerman 23 Jan '01

23 Jan '01

On Tue, Jan 23, 2001 at 08:10:36PM -0800, Sean Donelan wrote: > The most popular commercial web sites appear to have enough alternate > paths, so they didn't appear affected. I did notice a bit of difficulty > in some banner ads loading, and other web page fillers. Which leads to > an interesting problem for web site owners. Your own content may load > quickly, but the user will be watching the spinning icon on their web > browser for a long time. Most banner ads are of predetermined size, displayed using <IMG> tags with size attributes, so page rendering can be done before the image has been downloaded. So, the user should be able to see the content right away, even if the ads take a while to fill in. Sites whose ads don't work this way are broken. HTML ads, of course, can't be fixed this way, so if your site is pulling HTML ads from an ad server, it should time out aggressively when the ad server doesn't respond. -- - mdz

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Tricky BGP into IGP Question
by Tim Wolfe 23 Jan '01

23 Jan '01

What is the preferred way to get transit customers routing information into your IGP so that BGP will announce the route to it's neighbors. 1===2a===2b====3 | 4 1 is the customer, announcing to 2a, who propogates 1's route to 2b and to 4. 2b will not announce the route to 3 as it doesn't have a route in it's routing table for 1's route. I was thinking about redistributing bgp into my igp using a route-map based on as-path filter, but that seems somewhat kludgy. What are you all doing to accomplish this or am I just missing something here? Thanks, --Tim ============================================= Timothy M. Wolfe CCNA, NSA Sr. Security Engineer tim(a)ignw.com InfoGroup Northwest 541.485.0957 x108 =============================================

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Re: Tricky BGP into IGP Question
by Danny McPherson 23 Jan '01

23 Jan '01

I this 'trick' you're looking for is that of disabling BGP synchronization (i.e., 'no synchronization' in IOS parlance). Putting external things in your IGP is a really BAD idea, BTW. -danny > What is the preferred way to get transit customers routing information into > your IGP so that BGP will announce the route to it's neighbors. > > 1===2a===2b====3 > | > 4 > > 1 is the customer, announcing to 2a, who propogates 1's route to 2b and to > 4. 2b will not announce the route to 3 as it doesn't have a route in it's > routing table for 1's route. I was thinking about redistributing bgp into > my igp using a route-map based on as-path filter, but that seems somewhat > kludgy. What are you all doing to accomplish this or am I just missing > something here?

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Broadwing Fiber cut, El Paso, TX
by Majdi S. Abbas 23 Jan '01

23 Jan '01

Broadwing is working on repairing a fiber cut in El Paso, TX. Their master ticket is 3677, with a current ETA of 6 hours. Expect lots of down-haul connectivity. --msa

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Re: clue for the clueless please
by Ryan O'Connell 23 Jan '01

23 Jan '01

On Tue, Jan 23, 2001 at 01:59:41PM -0000, Peter Galbavy wrote: > Yes, we intentionally (for some other reason during testing) set the MTU on > the p2p link to 554 - oops. Will get it switched back... Still wondering > though - if a normal dial-up has a lower than 1500 MTU, why would they work. Sounds almost certainly like an MTU problem. Try www.bt.com, if that fails then it's pretty much definite. Microsoft are a bit silly for setting the DF bit on outbound packets, firewalls at web hosting facilities that block all ICMP are even more silly. Why on earth Microsoft, who must know about this problem, block ICMP on their kit I don't know... Most if not all dialup has an MTU of 1500. -- Ryan O'Connell - <ryan(a)complicity.co.uk> - http://www.complicity.co.uk I'm not losing my mind, no I'm not changing my lines, I'm just learning new things with the passage of time

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