En allumant la Bbox TV j'ai ça:
root@OpenWrt:~# tcpdump -i eth1 igmp -vv
tcpdump: listening on eth1, link-type EN10MB (Ethernet), capture size 262144 bytes
09:59:53.743113 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 224.0.0.251: igmp v2 report 224.0.0.251
10:00:03.193018 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 224.0.0.251: igmp v2 report 224.0.0.251
10:00:05.913002 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 224.0.0.251: igmp v2 report 224.0.0.251
10:00:10.573050 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.255.250: igmp v2 report 239.255.255.250
10:00:12.952976 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.255.250: igmp v2 report 239.255.255.250
10:00:16.632968 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 224.0.0.251: igmp v2 report 224.0.0.251
10:00:18.002995 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.3.22: igmp v2 report 239.255.3.22
10:00:18.552961 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.255.250: igmp v2 report 239.255.255.250
10:00:22.152957 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.3.22: igmp v2 report 239.255.3.22
10:00:24.312993 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.211: igmp v2 report 232.0.64.211
10:00:24.713056 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.3.22: igmp v2 report 239.255.3.22
10:00:31.992951 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.211: igmp v2 report 232.0.64.211
10:00:33.522390 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > all-routers.mcast.net: igmp leave 232.0.64.211
10:00:36.072933 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.255.250: igmp v2 report 239.255.255.250
10:00:37.992908 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.3.22: igmp v2 report 239.255.3.22
10:00:41.592926 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 224.0.0.251: igmp v2 report 224.0.0.251
10:01:34.192748 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.211: igmp v2 report 232.0.64.211
10:01:35.752753 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.211: igmp v2 report 232.0.64.211
10:01:43.225752 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > all-routers.mcast.net: igmp leave 232.0.64.211
10:01:50.712698 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.3.22: igmp v2 report 239.255.3.22
10:01:51.352730 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 224.0.0.251: igmp v2 report 224.0.0.251
10:01:54.552670 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.255.250: igmp v2 report 239.255.255.250
10:02:43.762585 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.211: igmp v2 report 232.0.64.211
10:02:52.794354 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > all-routers.mcast.net: igmp leave 232.0.64.211
10:02:55.752562 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.255.250: igmp v2 report 239.255.255.250
10:02:59.272508 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 224.0.0.251: igmp v2 report 224.0.0.251
10:03:03.672554 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.3.22: igmp v2 report 239.255.3.22
tcpdump: listening on eth1, link-type EN10MB (Ethernet), capture size 262144 bytes
10:09:14.445736 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.211: igmp v2 report 232.0.64.211
10:09:16.355553 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.211: igmp v2 report 232.0.64.211
10:09:19.475661 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.211: igmp v2 report 232.0.64.211
10:09:23.489652 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > all-routers.mcast.net: igmp leave 232.0.64.211
10:09:25.545535 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.255.250: igmp v2 report 239.255.255.250
10:09:31.955588 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 224.0.0.251: igmp v2 report 224.0.0.251
10:09:33.235582 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.3.22: igmp v2 report 239.255.3.22
10:09:54.745760 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.204: igmp v2 report 232.0.64.204
10:09:55.375634 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.204: igmp v2 report 232.0.64.204
10:10:00.115595 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.204: igmp v2 report 232.0.64.204
10:10:03.786759 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > all-routers.mcast.net: igmp leave 232.0.64.204
10:10:08.035565 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.255.250: igmp v2 report 239.255.255.250
10:10:10.435586 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.3.22: igmp v2 report 239.255.3.22
10:10:14.835548 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 224.0.0.251: igmp v2 report 224.0.0.251
10:10:15.765661 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.205: igmp v2 report 232.0.64.205
10:10:22.515572 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 232.0.64.205: igmp v2 report 232.0.64.205
10:10:24.806699 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > all-routers.mcast.net: igmp leave 232.0.64.205
10:10:29.075564 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.255.250: igmp v2 report 239.255.255.250
10:10:35.955558 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 239.255.3.22: igmp v2 report 239.255.3.22
10:10:36.595552 IP (tos 0xc0, ttl 1, id 0, offset 0, flags [DF], proto IGMP (2), length 32, options (RA))
Bouygtel4K-272011032208462.lan > 224.0.0.251: igmp v2 report 224.0.0.251