IGMPv3 receiver can get streaming with v3 querier but failed with v2 querier on the same switch

[Qunli Zhang]

Dear Networkers,

When SW_2(2960-X, v15.2) sends the IGMPv2 membership Query(seems I cannot make it to send v3 queries), the client/receiver in IGMP v3 only mode replied the membership Report to 224.0.0.22.

But “show ip igmp snooping group” on the cisco SW_2 doesn’t list the port and the joined multicast group. Also the receiver cannot get the multicast streaming.

Show ip igmp snooping command shows that IGMPv3 snooping is enabled(though “minimal” mentioned there)

SW-2960-X#sh ip igmp snooping vlan 107

Global IGMP Snooping configuration:

-------------------------------------------

IGMP snooping                : Enabled

IGMPv3 snooping (minimal)    : Enabled

After I added one router in the VLAN, disabled the igmp querier feature on the SW2, made the Router_1 as the IGMP querier with IGMP v3,  the same “show ip igmp snooping group” listed the client interface and the multicast group it joins, the stream can reach the receiver from the source.

SW-2960-X#sh ip igmp snooping groups
Vlan      Group                    Type        Version     Port List
-----------------------------------------------------------------------
107       224.0.1.40               igmp        v3          Gi1/0/17
107       225.1.1.1                igmp        v3          Gi1/0/17, Gi1/0/19, Gi1/0/21

I am wondering why the switch_2 behaves differently between the IGMPv2 querier and V3 querier.  The receiver is always sending the IGMP v3 report during the two scenario.

Thanks for your explanation.

[Philip D'Ath]

What are the switches and what software version are you using on them?

[Qunli Zhang]

The SW_2 in the diagram is one 2960-X with IOS 15.2(2)E6.

[playerplease]

if your switch can only talk igmpv2 then he won't be able to understand the igmpv3 membership reports sent on 224.0.0.22. So no snooping I think :(

[paul driver]

Hello

I am wondering why the switch_2 behaves differently between the IGMPv2 querier and V3 querier

Playerplease is correct - When snooping is enabled the switch it doesn't understand igmp v3 messages, so options i guess would be disable snooping or user igmpv2 on the interfaces instead

res
Paul