05-03-2017 02:05 AM - edited 03-08-2019 10:25 AM
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.
05-03-2017 04:48 AM
What are the switches and what software version are you using on them?
05-04-2017 01:39 AM
The SW_2 in the diagram is one 2960-X with IOS 15.2(2)E6.
08-13-2017 09:53 PM
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 :(
08-14-2017 01:29 AM
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
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