On Sat, Feb 14, 2004 at 01:49:05PM -0500, Stephen J. Wilcox wrote: > On Sat, 14 Feb 2004, Sven Huster wrote: > > > > > On Sat, Feb 14, 2004 at 12:46:09PM -0500, Stephen J. Wilcox wrote: > > > > Dumb question: > > > > If I apply a equal weight to all our transit/peers, will > > > > that affect route announcements to iBGP or eBGP peers anyhow? > > > > > > No it wont affect announcements, weight is local to the router you apply it. > > > > > > > What I want to achieve is that traffic leaves through > > > > the border router it arrived, rather than have it bounced around. > > > > > > eBGP should be preferred over iBGP anyhow assuming all other things are equal, > > > if theyre not equal then either make them equal or you probably want to choose a > > > different path anyhow (eg shorter as path). > > > > > > if you dont want any traffic to go across your network why bother meshing the > > > ibgp in the first place? > > > > Just to make it a bit more clear: > > > > Transit1 Peers Transit2 Peers Customers via BGP > > | | | | | > > ----R1---- ----R2---- R3 > > | | | > > | | | > > | | | > > ---------------------Core--------------------- > > | > > | > > Data Center > > > > Full-mesh between R1,R2,R3 and Core > > > > > > We carry traffic from the DC as well as the customers in the core to transit and > > peers. > > We normally want to advertise full routes to customers, which are multi-homed. > > > > > > > > > We had some recent issues were it looks like the core got "out of sync" with > > > > the border (looks more like a sw issue than just convergence delay) and > > > > packets bounced back and forth between them. I know this doesn't solve the > > > > cause but the before digging for the initial reason I want a quick workaround. > > > > > > hmm, i'd suggest emergency maintenance before doing some weird screwy stuff like > > > that :) > > > > The thing that happend was that the core believed that the best path out is via > > R1, which R1 thought it was via R2. So a little loop there. > > > > We weren't able to reproduce the problem nor to find a source yet. > > Is this all the same vendor hardware?
Nope. R1-3 - Cisco Core - Extreme Alpine 3808 > > Check the bgp configs are identical eg deterministic-med, dampening, > always-compare-med etc are all configured the same.. I'll have a look there. Thanks Sven