[PATCH v2] babel: Add support for dual-stack v4/v6 operation

[Juliusz Chroboczek]

>> BTW, are third-party next hops allowed in Babel? I checked RFC 6126
>> but found nothing.

They're not forbidden, but I don't think they are useful.  There's no
reason I can see why they wouldn't work, but I haven't actually tested.

> Not sure how babeld will react to non-LL next hop addresses...

They're allowed.  RFC 6126 4.4.8 says

  AE        The encoding of the Address field.  This SHOULD be 1 or 3
            and MUST NOT be 0.

This means that the next-hop SHOULD be either IPv4 or link-local IPv6, but
may also be a global IPv6 address.  I don't think I've ever tested babeld
with global IPv6 next-hops, but if it doesn't work, it's a bug.

-- Juliusz