Hi all,
I have 1 Nexus 3548 switch in each Data Centre spanned across to each other. One switch is Layer 3 the other is Layer 2 for vlan 899.
Switch A (Layer 3 for vlan 899) doesn't seem to be processing IGMP membership reports requests from hosts on Switch B (layer 2 vlan 899). The port-channel across sites is Po1 configured on both switches, mrouter port for vlan 899 is Po1 on both switches. However "sh ip mroute" on Switch A doesn't show these 2 particular hosts on Switch B. IGMP snooping is enabled.
If I span traffic to a Wireshark box for both hosts on Switch B I can see IGMP traffic every 15 seconds leaving (v2 IGMP Member reports), however if I span Po1 on Switch B or Port 1 on Switch A I do not see these host requests. I see plenty of other multicast packets going across Po1 on both switches working fine, it's just this one particular IGMP group I cannot see.
The fact I cannot see the hosts IGMP queries on Switch B Po1 suggests to me to me that Switch B's Control Plane is doing something weird with these packets and not processing them. My 1st thought was to turn off IGMP snooping for this particular group but not ideal. This problem appeared after I upgraded the code on Switch A (L3 for vlan 899) to 7.0(3)I7(6)....... Switch B (L2 for vlan899) is running 6.0(2)A8(4a)...I excluded Switch B from the upgrade when I discovered the problem Monday after application teams showed me.
Switch B
# show ip igmp snooping mrouter vlan 899
Type: S - Static, D - Dynamic, V - vPC Peer Link
I - Internal, F - Fabricpath core port
C - Co-learned, U - User Configured
P - learnt by Peer
Vlan Router-port Type Uptime Expires
899 Po1 D 1w3d 00:04:58
# show ip igmp snooping vlan 899
IGMP Snooping information for vlan 899
IGMP snooping enabled
Lookup mode: IP
Optimised Multicast Flood (OMF) disabled
IGMP querier present, address: 10.210.89.2, version: 2, i/f Po1
Switch-querier disabled
IGMP Explicit tracking enabled
IGMPv2 Fast leave disabled
IGMPv1/v2 Report suppression enabled
IGMPv3 Report suppression disabled
Link Local Groups suppression enabled
Router port detection using PIM Hellos, IGMP Queries
Number of router-ports: 1
Number of groups: 61
VLAN vPC function disabled
Active ports:
Po1 Po3 Eth1/8 Eth1/15
Eth1/24 Eth1/28 Eth1/29 Eth1/40
Eth1/44 Eth1/45
Switch A
# sh ip igmp snooping vlan 899
Global IGMP Snooping Information:
IGMP Snooping enabled
Optimised Multicast Flood (OMF) enabled
IGMPv1/v2 Report Suppression enabled
IGMPv3 Report Suppression disabled
Link Local Groups Suppression enabled
IGMP Snooping information for vlan 899
IGMP snooping enabled
Lookup mode: IP
Optimised Multicast Flood (OMF) enabled
IGMP querier present, address: 10.210.89.2, version: 2, i/f Vlan899
Querier interval: 125 secs
Querier last member query interval: 1 secs
Querier robustness: 2
Switch-querier disabled
IGMPv3 Explicit tracking enabled
IGMPv2 Fast leave disabled
IGMPv1/v2 Report suppression enabled
IGMPv3 Report suppression disabled
Link Local Groups suppression enabled
Router port detection using PIM Hellos, IGMP Queries
Number of router-ports: 1
Number of groups: 73
VLAN vPC function disabled
Active ports:
Po1 Po3 Eth1/8 Eth1/15
Eth1/24 Eth1/28 Eth1/29 Eth1/40
Eth1/44 Eth1/45
Report Flooding: Disabled
Interfaces for Report Flooding: n/a
Use Group Address for Proxy Leaves: no
# sh ip igmp snooping mrouter vlan 899
Type: S - Static, D - Dynamic, V - vPC Peer Link
I - Internal, F - Fabricpath core port
C - Co-learned, U - User Configured
P - learnt by Peer
Vlan Router-port Type Uptime Expires
899 Vlan899 ID 1w3d 00:03:49
