bgp behavior with exchange prefix in ebgp
Gert Doering gert at space.net
Fri Sep 5 10:24:22 CEST 2003
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
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