[Sussex] IPv6 question

[Alan J Fitton]

Hi, anyone have any experience with IPv6? I've got an IPv6 interface up
and working, with a /64 address prefix. Reverse DNS works ok too (Which
works over IPv4, but I assume this is only while it is in testing).

2^(128-64) = 18446744073709551616 addresses I can use. I won't pretend I
have something to do with them all :)

Main problem is that when I assign the address 2001:470:1f01:423::/64 to
the sit1 interface, I can use 2001:470:1f01:423:: address, but anything
beyond that in the /64 doesn't work at all. The ifconfig (latest version)
man page seems to suggest it should work. Adding each address individually
works, so they are being routed beyond my box...

sit0      Link encap:UNSPEC  HWaddr
00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
          inet6 addr: ::127.0.0.1/96 Scope:Unknown
          UP RUNNING NOARP  MTU:1480  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:25 errors:1 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 b)  TX bytes:3100 (3.0 Kb)

sit1      Link encap:UNSPEC  HWaddr
00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
          inet6 addr: 2001:470:1f01:423::/64 Scope:Global
          inet6 addr: 2001:470:1f01:ffff::287/127 Scope:Global
          inet6 addr: fe80::a00:6/64 Scope:Link
          UP POINTOPOINT RUNNING NOARP  MTU:1480  Metric:1
          RX packets:15151 errors:0 dropped:0 overruns:0 frame:0
          TX packets:24191 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:2387301 (2.2 Mb)  TX bytes:2559172 (2.4 Mb)

One thing I don't understand still (might not need any IPv6 experience to
work this out): what is the highest possible address in each colon
seperated part of the address? I think it's ffff, not sure.

Next thing is to maybe try iptables for the beast, but there's no
connection tracking so I might not bother for now.

Cheers,
Alan