After booting a nova-compute node, IPv6-enabled instances have buggy IPv6 connectivity, with packets coming through sporadically. This appears to be caused by the radvd started by nova-network using a wrong MAC address in router advertisements:

[root@i-00000036:~]# rdisc6 eth0
Soliciting ff02::2 (ff02::2) on eth0...
...
 Source link-layer address: 66:AD:2A:A5:D9:19
 from fe80::64ad:2aff:fea5:d919

The MAC address 66:AD:2A:A5:D9:19 doesn’t match the bridge device on which radvd is listening:

[root@stan:~]# ifconfig 
br100     Link encap:Ethernet  HWaddr FE:16:3E:2E:C4:E4  
...

Killing radvd and restarting nova-network fixed this:

[root@i-00000036:~]# rdisc6 eth0
Soliciting ff02::2 (ff02::2) on eth0...
...
 Source link-layer address: FE:16:3E:2E:C4:E4
 from fe80::64ad:2aff:fea5:d919

Cause unknown. Might have to do with the MAC addresses of the enslaved interfaces (vnetN).

Submitted by Eelco Dolstra on 20 June 2011 at 18:14