nanog mailing list archives

Re: AT&T NYC


From: alex () yuriev com
Date: Tue, 3 Sep 2002 08:43:09 -0400 (EDT)


problem on unaffected route?  

Ask your customers. They do not care if someone else is having a problem.
They care that they dont. 

Do you run a decent sized network?

No, I have never touched a router in my life. 

Possibly..

Convergence time in the order of that taken by BGP is not acceptable,
things go crazy when traffic pours in and theres no routes to carry it.

This is a great blanked statement. What is convergence time?

The time from when traffic starts hitting down interfaces or null to when it
starts going again. Preferably without the rest of the network needing to know
about it and suffer meltdown.

How many seconds does it take your network to meltdown from traffic?

Other example, what about static dialup users, they dial up and wait a few
minutes whilst their route is installed throughout BGP??

That is why their route is *nailed* via BGP to the router that *always*
provide connectivity to them. If they have to move, BGP injectors are your
friends. Takes seconds.

See previous comment about network size - theres no such thing as always in
dialup with multiple geographic PoPs.

Route-injection is your friend. 
bgp-push and avi-bgp are your friends.

With link-state, one interface flap can mean doing SPF on every route.
If "every route" is only a couple hundred, rather than 100K, you fare

As you say disable synchronization and try and control the physical reach of
your igp by some mechanism.. areas, summaries, ASes etc

Which is exactly what you are doing when you inject nailed routes into bgp.

No its not? I'm suggesting some level of order can help control the number of
routers required to reconverge a network, I dont see the comparison with
inserting routes in BGP which is how the routes get in not how they converge.

If you dont have a network wide meltdown due to IGP failure you wont need to
wait for entire network to come up. It is timing of discrete events.  Isn't
math grand.

Reconvergence after a single link failing is hardly failure/meltdown?

How many SECONDS does it take to for your network to meltdown from normal
traffic level?


Alex

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