Harry, I'm still working to reproduce this, without success. I have set the .autoconf sysctl to 0 (which controls creation of local addresses in response to received Router Advertisements), as well as setting .addr_gen_mode to 1 (to disable SLAAC (fe80::) addresses).
In any event, .autoconf=0 and .addr_gen_mode=1 still fails to reproduce the issue on my test system. I find that if I disable mcast_flood on the relevant bridge ports (i.e., bridge link set dev vnet1 mcast_flood off) I do see the behavior you describe, but in that case no variant that I've tried (no vid, and all vids in use) of "bridge mdb add ... grp ff02::1:ff00:2" appears to permit ND traffic to pass to the VM destination. Can you provide more specifics of how exactly the bridge and ports are configured? Ideally, both the method to set it up, as well as the configuration details when failing (i.e., "ip -s -d link show" for the bridge and relevant bridge ports, "bridge vlan show", "bridge mdb show", "bridge fdb show br [bridgename]") Also, to answer a question from your original report, the default setting in the kernel for multicast_snooping (enabled, i.e., 1) hasn't changed recently (and quite possibly ever). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1959702 Title: Regression: ip6 ndp broken, host bridge doesn't add vlan guest entry to mdb To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1959702/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs