[Xorp-users] IPv6 & BGP

Hasso Tepper hasso@linux.ee
Sat, 17 Dec 2005 20:08:41 +0200


Mark Handley wrote:
> On 12/17/05, Kristian Larsson <kristian@juniks.net> wrote:
> > I'm having problem setting up a v6 only BGP
> > connection. it would seem it requires a next-hop
> > parameter which is v4. Since I don't have v4 on
> > this machine at all it is difficult.
> > Please advice
>
> The BGP spec requires a NEXTHOP attribute in all routes, and this is
> specified as an IPv4 address.  It needs this even if you're running
> IPv6 only, but it shouldn't be used for the routing calculation.  I've
> not tried it (probably Atanu has) but you should be able to specify
> 10.0.0.1 or something similar.

Sorry, but this is nonsense.

>From draft-ietf-idr-rfc2858bis-07.txt (the same text is there in the 
RFC2858 as well):

"An UPDATE message that carries no NLRI, other than the one encoded in
the MP_REACH_NLRI attribute, SHOULD NOT carry the NEXT_HOP attribute.
If such a message contains the NEXT_HOP attribute, the BGP speaker that 
receives the message SHOULD ignore this attribute."


-- 
Hasso Tepper