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? Check the bgp configs are identical eg deterministic-med, dampening, always-compare-med etc are all configured the same.. Steve > So the plan right now was: if the core decides that traffic should go out via > R1, R1 just just send it out via the best path it got from eBGP. > So that we get some more time for debugging what's going on there. > > Sven > >