On 2/21/18 1:24 PM, Ido Schimmel wrote: >>> Does it matter if you try IPv4 ping or if vlan_filtering is set 1? >>> Unfortunately, I can't reproduce on my switch. >> >> Bring up the hosts and then reboot the switch. At that point I get no >> host to host communication. As soon as I flap the port on host1 host3 to >> host1 starts working. >> >> So it seems to be something about the initial boot state. > > You didn't have IPv6 *and* IPv4 ping? I'm asking because it's possible > host1 sent an MLD join to the Solicited-node multicast address before > the bridge started listening, which means it didn't have a corresponding > MDB entry.
The sim only configures IPv6, but it is not acting as an mcast router. It's really a dummy setup -- bridge on the switch, ports connected to hosts. > > Assuming your hosts aren't functioning as multicast routers and sending > MLD queries and that you didn't configure them as mrouter ports on the > switch, then when host3 sent a neighbour solicitation message to host1's > Solicited-node multicast address it wasn't flooded to host3 which > prevented ping from passing. > > This also explains why it started working when you flapped the port on > host1, as Linux generates MLD joins in these cases. > > You can try to disable snooping: > > # ip link set dev br0 type bridge mcast_snooping 0 > > Just a guess, but worth a try. good guess. That change gets it working.
