How can I configure a BIRD router to communicate to a neighbor on a different subnet with RIPv2?

[Ondrej Zajicek]

On Mon, Jul 25, 2016 at 04:58:53PM -0400, Travis Pressler wrote:
> I'm attempting to set up basic communication with the RIPv2 protocol with BIRD v1.6.0. 
> 
> I've got `Host A` with an interface `enp0` that has address `10.0.1.50/24`.           
> I've got another host `Host B` with an interface `enp1` that has address `10.1.1.25/24`
> These interfaces are directly connected by cable. I can ping between both machines if I add a static route on both machines.
...
> If I run 'echo all' in the bird command line I see this message: 
> 
>     >>> MyRIP: Bad packet from 10.1.1.25 via enp2s0f0 - not from neighbor (0)
> 
> How can I get these routers to list each other as neighbors if the two ends of the link aren't on the same subnet?

Such configuration is not allowed, as the source address check is required
by RIPv2 specification, RFC 2453:

  The datagram's IPv4 source address should be checked to see whether the
  datagram is from a valid neighbor; the source of the datagram must be on
  a directly-connected network.

-- 
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."