I ask because the server is handling DHCPv6 for two VLANs and I can see some requests both via DHCPv6-relay from our ProCurve switch and via the ff02::0:2 anycast address and responds to both requests.
The logs look like this:
Sep 23 00:40:05 fry dhcpd: Request message from fe80::2c0:b7ff:fe53:32e7 port 546, transaction ID 0x7C08E400 Sep 23 00:40:05 fry dhcpd: Sending Reply to fe80::2c0:b7ff:fe53:32e7 port 546 Sep 23 00:40:05 fry dhcpd: Relay-forward message from 2001:1900:221c:800::1 port 547, link address 2001:1900:221c:800::1, peer address fe80::2c0:b7ff:fe53:32e7 Sep 23 00:40:05 fry dhcpd: Sending Relay-reply to 2001:1900:221c:800::1 port 547
I suppose it might be possible to enable DHCPv6 relay only for one of the VLANs and use anycast for the other, but it seems cleaner to me to have them both serviced in the same way.
This is on Ubuntu 11.04 with a 4.2.2 dhcpd I compiled myself (without changing anything). The same behavior happens with the regular 4.1 Ubuntu package, however.