[j-nsp] IPv6 '::' as source address

[Pekka Savola]

Hi,

These issues are non-impacting for us, so I didn't want to bother to 
create PRs through our support contacts, but maybe someone from 
juniper will pick them up as they seem obvious enough..

I had noted this in the past, but while a neighbor router rebooted, I 
got this again on 7.5R2..:

Apr 12 09:10:29 xxx0-rtr /kernel: mld6_input: src :: is not link-local (grp=0400:0:ff02::)
Apr 12 09:10:29 xxx0-rtr /kernel: mld6_input: src :: is not link-local (grp=0400:0:ff02::0001)

Two issues:
  1) the group address seems to have 64 bits in flipped order, as the
     group addresses should start with ff02...  I'm assuming this is a
     printing problem, not a wire encoding issue (the other end is also
     juniper)

  2) implementing RFC 3590 would be nice, because it's OK to send MLD
     reports with :: as source address.

While I'm at it, I'll also mention that apparently IPv6 uRPF drops 
packets with '::' source address which hampers duplicate address 
detection (RFC 2461).. maybe a ::/128 route should be installed on all 
the interfaces or something to get away from this issue.

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings