On Mon, 2 Sep 2002 alex@yuriev.com wrote:
Has anybody mentioned the benefits of ISIS as an IGP to them.
Link-state protocols are evil, and when they break, they *really* break. I still do not see a compeling argument for not using BGP as your IGP.
Convergence time?
What is better - relatively long convergence time on affected routes or a 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? 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. Other example, what about static dialup users, they dial up and wait a few minutes whilst their route is installed throughout BGP??
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. Steve
So, why do you need IGP such as OSPF again?
Alex