North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: BGP vs. static routing (Re: Why Vadim likes statics)
> > > In message <[email protected]>, [email protected] writes: > > | This sounds a lot like the slippery slope of static routing being the most > | stable, so we should encourage its use Internet wide. I -know- Karl D. > | (and others that depend on dynamic routing for alternate provider fallback) > | will kick at this. > > Why? What we have been arguing for has been limiting > the scope of dynamic routing only to places where > participating in global dynamic routing makes sense. So it does not make sense for IBM or Sony to run dynamic routing in their internal networks?!? > The border router does aggregation outbound and points the > aggregates at Null 0 with a high metric. True. > This is for cases in which there is no other router > participating within the customer iBGP mesh, and where there > are N (N>=1) upstream providers, and where dynamic routing > must take place within the ISP's routing domain for various > reasons (portable dialup links, links that are time-sensitive, etc.) The assumption in this case is a common egress point. > The iBGP box should do aggregation and have static routes > pointing to Null0 for all nets it announces to the two edge > routers. Again, a common egress point is assumed and to differeniate policy by provider will involve netlists. > A more complex case is one like this: > > Provider X Provider Y Peers A, B, Z > | | | > +--------+ +--------+ +---------+ > | | | | | | > +--------+ +--------+ +---------+ > \ | / > (a bunch of iBGP-talking routers) > > at this point people are building something akin to what > NSPs do. > .............. > Step 2 is to do the _same_ aggregation and high-metric > routing to Null 0 on all the border boxes (the three shown > above) so that a consistent picture of this small-i internet > is presented to the outsides world. The assumption here is that there is a consistant policy from this ISP to all its peers. This may not be true. (I am working at a site which is an existance proof) > I'd detail several more steps but my fingers tell me they > want to go on to the next message. No problem... --bill
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