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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: AT&T NYC
> > Rubbish again. > > > > *Every* interface that you bring up has a connected route. You redistribute > > those routes into IGP. You redistgribute statics from that router into IGP. > > Nail those routes into bgp and set internal community on it. > > > > network xxx.yyy.zzz.www mask ppp.hhh.ooo.lll route-map set-igp-community. > > So how does this provide equivalent functionality to "compare igp > metric"? First of all, did we agree by now that there is no scalability issue or do we need to go over this again? > I think there are a lot of folks out there who might like > to do the whole nearest-exit thing. set metric +1 is your friend. > Even if you went to the trouble > of setting up route-maps to your heart's content and managed to get > each router to prefer paths from the nearest exit router, it wouldn't > do you much good when a link failure turns that "nearest" into > "furthest" but the iBGP session stays up. You metric would be appropriately affected. next-hop-self and confederations are your friends. > I think maybe the word "need" is being taken a little too seriously > here. No, you don't NEED a separate IGP to make BGP work. But then > again, you don't NEED a lot of things to make a network go in its > most basic form. However, without some of those "unnecessary" things > you might not find it to perform quite to your liking either. For my > network, I'd much rather deal with some extra SPF calculations than > slow convergence and playing route map games to get things like > nearest-exit working. There are no route-map games. You can basically have the same route-map on all internal links. Of course it requires to be able to construct logical "if then" trees, as well as know some fundamental algebra. > Links and loopbacks => IGP > Everything else => BGP IGP trouble -> entire network down with hundreds of otherwise unaffected customers experiencing connectivity problems and getting hard earned $$ back, sending yet another network into ochapter 11. > But then, nobody ever accused any two engineers of having the same > personal preferences... > > -c > > --
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