Juliusz Chroboczek <jch@pps.univ-paris-diderot.fr> writes:
If this is not the case, I think the RFC needs to specify what, exactly, is meant by a "wildcard address". I've always thought of ::/0 as the wildcard address; and doesn't "default route" also mean "wildcard route"?
Wow, no.
Yes, feel free to marvel at my ignorance ;)
For example, a request for 2000::/3 requests an update for 2000::/3. If a router has routers for 2000::/4 and 3000::/4 but no route for 2000::/3, it must not use the longer prefixes to satisfy a request for 2000::/3 -- from the router's point of view, there's no relation between the prefixes.
That I did know.
AE 0 is used to mean "any" in the following circumstances:
- IHU (where it represents "any" interface identifier); - non-seqno request (where it represents "any" prefix); - retraction (where it represents "any" prefix).
It is not allowed in any other place -- in other places, RFC 6126 says that AE MUST NOT be 0. (There's an omission in Section 4.4.9, where it only says in what case AE MAY be 0; the implication is that it MUST NOT be 0 in other cases.)
Hmm, maybe this should be spelled out somewhere? Otherwise you'll just have problems with people unfamiliar with such basic constructs of routing protocols trying to implement the protocol; who knows where that might lead? :)
If we decide to make an incompatible revision of Babel, I might decide to remove AE 0. While it seemed like a good idea at the time, it's turned out to only be moderately useful -- the retraction case can be handled by announcing a Hell interval of 10ms (which causes the neighbour to drop after 0.16s), and the other uses are not useful.
Fine with me :) -Toke