Config multicast for 3 inter-connecting switches

[Ian.Poh]

Hi,

If i have 3 switches in the most basic setup where 1 is root bridge and all are inter-connected via LACP/port-channel, how should multicast be configured? Drawn a simple diagram here. LACP are workings and VLAN 10 is allowed for the trunks.

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series-switches/68131-cat-multicast-prob.html

Based on above link info, if i adopt Solution 2, the switches should be configured as below:

On Switch 1

- Configure mrouter on Port-Channel 1 and Port-Channel 2 for SW1

On Switch 2

- Enable Querier on VLAN 10

On Switch 3

- Enable Querier on VLAN 10

Am i correct?

Thank you so much for the advise.

[ngkin2010]

If you adopt Solution 2, you don't need to enable mrouter on Port-Channel 1 and Port-Channel 2.

Querier (SW2 and SW3) will periodically send out IGMP query within VLAN10. If you have enabled IGMP snooping on the switches, they will able to inspect the IGMP message (responding to the IGMP query) from IGP groups' members. So, the IGMP snooping will work.

On the other hand, if you adopt solution 3, which mean there is no neither multicast router nor IGMP querier in VLAN10. Then, you need to promote at least 1 of the switch to become multicast router on VLAN10. The multicast router role here is not used to route the multiact traffic, but to generate IGMP query. 

[Ian.Poh]

Thanks ngkin2010.

So i can approach in 2 ways i.e.

Method 1:

- Only need to enable VLAN 10 Querier for every of the switches i.e. for all 3 switch SW 1, SW 2 and SW 3?

Method 2:

- I only have to configure mrouter on Port-Channel 1 and Port-Channel 2 on SW 1, is that all?

Is my understanding correct?

Thanks again.

[Reza Sharifi]

Hi,

If everything is in one vlan, all you need is this command all layer-2 switches.

ip igmp snooping querier

 HTH

[paul driver]

Hello

Lan Multicast same vlan.
conf t
ip igmp snooping
ip igmp snooping vlan 10
ip igmp snooping querier  

[Ian.Poh]

Thank you everyone.

I will try it out.

Thanks again.