Router Server problem

Bill Woodcock woody at
Sun Dec 21 06:26:22 UTC 2003

    > ISP1------ RS1------- RS2 ------ ISP3
    >          |               |
    > ISP2------                --------ISP4
    > Now the routes injected by ISP1 into R1 are received by ISP2. And there is
    > exchange of routes between ISP3 and 4. But the routes send by ISP3 are not
    > seen by ISP1 and ISP2. But RS1 has got those routes in its data base.
    > These routes are not selected as best routes in the RS1 bgpd

It's sounding like you've perhaps got full routes, or at least overlapping
routes, learned from multiple sources, in the route servers.

My first recommendation would be to try to keep things simple by not
having anything other that IX participant peering (not full/transit)
routes in the route servers.

If that's not practical for some reason, then use an assigned metric,
applied when you learn the route, to cause it to be preferred.  It may be
that routes are not being selected because they're also being learned from
another source which has a lower IP address, the final tie-breaker in the
BGP route-selection algorithm.  Any higher-priority criterion, like
weight, would overcome the problem.


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