aptitude/apt-get hangs during update (plus) on IPv6

["Jeffrey B. Green" <jeff@kikisoso.org>]

Hi,

I'm seeing if there is an alternate answer here before filing a bug. (I
believe) All of the servers here that have IPv6 configured hang while
attempting an update on security.debian.org. If I turn off IPv6 by
deconfiguring the IPv6 address, then the update goes through fine.

When I check with tcpdump to be sure the firewall isn't the culprit, I
find that all of the packets that reach the firewall also make it to the
server and a conversation of 20-22 packets occurs (20 on one server, 22
on a different one). [If anyone wants to provide me with a state
transition diagram, or even a description, for the protocol aptitude
follows in doing the update, then I'd be happy to track down where
exactly in the process it hangs.] I can go back and forth with enabling
and disabling IPv6, and IPv4 always seems to work (just tried it with
one server).

Sooooo, if anyone knows what going on here or whether this looks like
an official bug, then let me know.

thanks,
-jeff