running two bird daemons which listen on loopback IP

[Ondrej Zajicek]

On Tue, Jun 19, 2018 at 05:34:06PM +0200, Pavlos Parissis wrote:
> Hi,
> 
> For testing purposes I want to run two bird instances which listen on two different IPs. Those IP
> addresses are assigned to loopback interface(Linux box). I have configured BGP but each daemon is
> waiting the other to become neighbor.
> 
> I run tcpdump on loopback interface and I don't see any network traffic, and I am wondering if
> using loopback inteface isn't supported.

Hi

It is likely unrelated to loopback. There are two cases:

BGP is EBGP (direct mode) - in this case BIRD checks if the destination
IP address is a direct neighbor and a local address is not considered
direct neighbor, so there is 'waiting to become neighbor' issue.

BGP is IBGP (multihop mode) - in this case it is regular TCP connection
and two local BIRD instances on two different local IPs work just fine.

You can switch to IBGP (same AS numbers) or just force multihop for
EBGP mode ('multihop' option).

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
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"To err is human -- to blame it on a computer is even more so."