AT&T NYC

Tue Sep 3 12:43:09 UTC 2002

> > > > 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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