Re: Regular Expression for IPv6 addresses

[sthaug () nethelp no]

> > And now for the trick question.  Is ::ffff:077.077.077.077 a legal
> > mapped address and if it, does it match 077.077.077.077?
>
> ::ffff:0:0:0:0/96 should never ever be shown to a user, as it is
> confusing (is it IPv6 or IPv4?) and does not make sense at all.
> As such whatever one thinks of it, it is "illegal" in that context.

Define "user"? Both Cisco and Juniper use these addresses for IPv6
L3VPNs, and the addresses are definitely visible. Cisco and Juniper
examples:

B    2001:abcd:60:3::/64
      [200/0] via ::ffff:172.16.101.204 (nexthop in vrf default), 4d10h
B    2001:abcd:60:4::/64
      [200/0] via ::ffff:172.16.101.205 (nexthop in vrf default), 4d10h
B    2001:abcd:60:7::/64
      [200/0] via ::ffff:172.16.1.7 (nexthop in vrf default), 6d13h


::ffff:172.16.1.1/128
                   *[LDP/6] 4d 11:01:30, metric 1
                    > to 172.16.102.201 via ge-0/3/0.0, Push 313008
::ffff:172.16.1.2/128
                   *[LDP/6] 1w0d 20:27:12, metric 1
                    > to 172.16.102.201 via ge-0/3/0.0, Push 312240
::ffff:172.16.1.3/128
                   *[LDP/6] 4d 11:01:30, metric 1
                    > to 172.16.102.201 via ge-0/3/0.0, Push 313024

Steinar Haug, Nethelp consulting, sthaug () nethelp no