As suggested by Herbert Xu (we exchanged a few private emails), I did a few tests on a simpler network scenario, with a three hosts setup like this: A e1 B e2 C where e1/e2 are ports on B. e1 and e2 are bridged, and there is hence just one bridge in the network. Here, I have done the following actions: 1) Setup a listener on A. When I do this, an IGMP report is generated by A and seen on node B. 2) Send some multicast packets to the group subscribed by A from B In this case, I get that multicast packets are seen by A but not by C. So, B is properly filtering the multicast messages, as expected. I have also tried a few variations of this test: -starting the listener on C, and I get that multicast messages are not received by A (maybe this is a too trivial test!) -changing the order in which the listener and the multicast source are started: I get that multicast messages are initially flooded (both A and B receive the messages), up to the point in which the listener starts on A, and C does not receive the messages anymore -setting the multicast_router flag to 0 -> no effect, IGMP snooping works as in the original test -setting the multicast_snooping flag to 0 -> multicast messages are received on A and C (as expected). I have also tested a scenario with 4 nodes A eb1 B eb2 ec1 C ec2 D where eb1/eb2 are ports on B, ec1/ec2 are ports on C. eb1/eb2 are bridged together as well as ec1/ec2, so there are now two bridges in the network, on node B and on node C. I have repeated the same test on the 3 nodes scenario, i.e., 1) setup a listener on A The IGMP report generated by A is seen on B and C (not on D) 2) Send some multicast packets to the group subscribed by A from B Multicast messages are seen on A and C, not on D. Is this correct? I would expect messages just on A, not on C. I have also repeated the test with the multicast_router flag set to 0, but I get the same behaviour. >----Messaggio originale---- >Da: maxd@xxxxxxxxx >Data: 31/05/2011 19.48 >A: <bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx> >Ogg: IGMP snooping not filtering multicast messages > >Hi. I have a partial mesh network composed by Linux nodes. Each linux node may >have up to 4 ethernet interfaces, which are exploited to create point-to- point >connections with other linux nodes. I have bridged the ethernet interfaces in >each node, so that the whole network, which is physically composed by a set of >network segments, appears as a single layer-2 domain. I have enabled spanning >tree to avoid loops. In this scenario, I would like to exploit the IGMP >snooping functionality, but it seems that it is not working properly. I am >using iperf to set a multicast source (iperf client) and a few multicast sinks >in the network (iperf servers). I am using tcpdump, instead, to check where >multicast messages are received. What I notice is that there is apparently no >filtering of the multicast messages, that are always flooded in the network. I >tried to repeat the test varying the multicast address (paying attention not to >get reserved addresses), with and without multicast clients set, with the >multicast_router option set to 1 (default) and to 0. To double check that IGMP >is working, I have also tried to disable it; the only difference I see is that >tcpdump does not show IGMP query messages when the IGMP snooping is disabled. >So, I am wondering if the IGMP snooping implementation currently available can >deal with my scenario. In particular, I would stress the following points that >I think might be relevant: >-I have no multicast router in my network (it looks like a single stand- alone >lan) >-Each node acts as a bridge, so I have multiple bridges in my network, >connected each other. >Any idea would be greatly appreciated! > >Massimiliano >_______________________________________________ >Bridge mailing list >Bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx >https://lists.linux-foundation.org/mailman/listinfo/bridge > _______________________________________________ Bridge mailing list Bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/bridge
