IPv6 support is a little rusty, but was working. I need to reestablish an IPv6 test environment here to continually exercise the code and figure out some remaining thorny issues. The last time I tried it, I could connect to remote systems via IPv6 using 6in4(8) but not local systems, and it appeared that Neighbour Discovery (the v6 equivalent of ARP, which uses multicast) was broken.
Some of the thorny issues are: - how best to operate in a mixed v4 and v6 world, where some hosts are v4-only, some are v6-only and some (eventually a lot) are capable of using both v4 and v6, preferably global (non-NAT, non-private, non-local) addresses. Is the ipv6 attribute of ndb actually useful, or should we just use the ip attribute for v4 and v6? - how to configure diskless v6-only (or almost only) machines at boot time? dhcp v6 seems pointless yet complex, v6 autoconfiguration might suffice with changes to implement dynamic dns, or dhcp v4 might be able to carry the necessary data. - how best to evade v4-only IP infrastructure (routers, firewalls, proxies, etc.). I'd be interested in hearing from anyone currently using v6 with Plan 9, particularly in Japan.
