Apparently, moving from zd1211rw to zd1211rw-mac80211 broke multicast (you
receive the multicast frames you sent) which in turn broke IPv6, see:
A report sent on netdev a couple of times, but no response. Slightly updated
On Fedora 7 (kernel 2.6.21-1.3228.fc7, based on 188.8.131.52; also kernel
184.108.40.206-41.fc7), my zd1211rw_mac80211 WLAN USB stick and multicast/v6 no longer
works. On Fedora 6 (kernel 2.6.20, no mac80211) it was OK.
I get "wlan0: duplicate address detected!" on dmesg when the kernel is trying to
autoconfigure a global address.
I suppose this is caused by the IPv6 stack seeing my own ICMPv6 neighbor
solicitation and thinking it was originated by someone
08:46:21.762807 00:02:72:5b:dc:28 > 33:33:ff:5b:dc:28, ethertype IPv6 (0x86dd),
length 78: (hlim 255, next-header: ICMPv6 (58),
length: 24) :: > ff02::1:ff5b:dc28: [icmp6 sum ok] ICMP6, neighbor solicitation,
length 24, who has
Strangely, the same error isn't printed with the link-local address which uses
the same EUI-64.
z1211rw Wiki seems to imply that this might be an issue in generic mac80211 code:
.. however, I suspect that there would have been a bigger outcry if that had
been the case.
*** This bug has been marked as a duplicate of 246305 ***