Re: [DNA] Re: RS/RA Exchange

[Erik Nordmark <Erik.Nordmark@sun.com>]

> So, I can dust off some "historic" code for this.  DVMRP has a HELLO
> message like many other routing protocols.  But, DVMRP uses them to
> announce reachability and discovery.  That is, peer routers on a link
> look in the other routers' HELLO messages for their own addresses.
> This allows them to determine when they have been "discovered" by
> their peers.
> 
> Could we mimic this and have some type of announcement message that
> a router would send out with all the other routers' addresses that
> it has heard from?

I don't think for this case (RA collision avoidance) we need the
confirmation of bidirectional reachability between the routers;
allowing each router to have an ordered list where the lists on
the different routers are loosly and approximately consistent should
be sufficient. Doesn't mean it would hurt to know that the routers
have a consistent view though.

One way to build this is to just interpret what is currently in the RA
messages.
Should this be insufficient and some new information needs to be
exchanged between the routers than it makes sense reusing something
which has already been built.
I don't know if there are related things that the routers might want
to advertise and coordinate with eachother.


  Erik