IP IGMP SNOOPING QUERIER

[singssf28]

Hi ,

In my project i am going to migrate one environment over to Fabricpath and also overlay of the vlans will be achieved using OTV.While working on the low level design i van see on the vlans IGMP querier is running so need suggestions on whether i still require to move the same configuration or not.Looking for your valuable suggestions.

[Peter Paluch]

Hello,

We know too little about the original design of the network to tell if the IGMP Snooping Querier has been truly needed. However, as a general rule, it will not harm to keep it active even after your migration. As far as FabricPath and OTV are concerned, they are oblivious to the presence of an IGMP Snooping Querier (FabricPath uses multidestination trees to carry the Broadcats, Unknown unicast, and Broadcast [BUM] traffic; OTV relies on either egress replication or underlay multicast to carry BUM traffic). However, for the edge and/or leaf switches, the IGMP Snooping Querier function is necessary to allow the switches learn about multicast subscribers and the groups they subscribe into, so deactivating IGMP Snooping Querier might introduce issues.

Therefore, my personal suggestion - in the absence of more detailed information about your network - is to keep IGMP Snooping Querier enabled even after the migration. It won't harm, and might actually be still required.

Best regards,
Peter

[singssf28]

Thanks Peter for your suggestion.Just another point instead of enabling querier on the layer 2 vlans if we run Layer multicast on SVIs i think it will work in the same manner.