Re: bgp behavior with exchange prefix in ebgp

[Gert Doering <]

Hi,

On Fri, Sep 05, 2003 at 10:18:45AM +0200, Iljitsch van Beijnum wrote:
> Note that the next hop points to an address that falls within the (old) 
> AMS-IX peering LAN prefix. Since this router isn't directly connected 
> to the AMS-IX, it needs to resolve this next hop:

Two ways to remedy this:

 - use next-hop-self on all iBGP peerings  (which isn't always the
   perfect choice, but will easily fix these issues)

 - filter the exchange prefix(es) for all IXes that you participate *and 
   all more specifics* on *all* eBGP sessions.  This is strongly recommended
   even when already using next-hop-self (more specifics can break eBGP
   sessions at the IXP peering routers)

Gert Doering
        -- NetMaster
-- 
Total number of prefixes smaller than registry allocations:  55575  (56535)

SpaceNet AG                 Mail: netmaster@localhost
Joseph-Dollinger-Bogen 14   Tel : +49-89-32356-0
80807 Muenchen              Fax : +49-89-32356-299