Quick question about multicast flooding/blocking... I know that by default a switch will forward multicast on all ports in the same broadcast domain. I think I've got it disabled with switchport block multicast and igmp snooping enabled on the multicast vlan (4004) on the 15.0(2)SE1 3560G-24TS I have running here. However, whenever I bounce a port configured with vlan 4004 on it (trunk or access), I get a period of 120 seconds where all ports in that VLAN are flooded with multicast traffic from Gi0/24. After 120 seconds has elapsed, the multicast traffic from Gi0/24 dies off and the flooding to any other connected vlan 4004 ports subsides.
There is an ME3600 connected to Gi0/24 and the multicast source is connected to an access port on that ME3600 in VLAN 4004. The switchport block multicast is configured there as well. It seems like I'm missing, or, have misconfigured a knob somewhere, but I'm not quite sure what or where. Any insight? ! interface range GigabitEthernet0/1 - 10 description Facing Client switchport trunk encapsulation dot1q switchport trunk native vlan 4082 switchport trunk allowed vlan 4004,4032,4082,4086 switchport mode trunk switchport block multicast switchport block unicast spanning-tree portfast ! interface GigabitEthernet0/24 description Facing Multicast Source switchport access vlan 4004 switchport block multicast switchport block unicast ! Systems-Dev_Pit#sh ip igmp snooping vlan 4004 Global IGMP Snooping configuration: ------------------------------------------- IGMP snooping : Enabled IGMPv3 snooping (minimal) : Enabled Report suppression : Enabled TCN solicit query : Disabled TCN flood query count : 2 Robustness variable : 2 Last member query count : 2 Last member query interval : 1000 Vlan 4004: -------- IGMP snooping : Enabled CAPWAP enabled : Disabled IGMPv2 immediate leave : Disabled Multicast router learning mode : pim-dvmrp CGMP interoperability mode : IGMP_ONLY Robustness variable : 2 Last member query count : 2 Last member query interval : 1000 Systems-Dev_Pit# Thanks in advance. _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
