IGMP Snooping and querier setup over multiple M4100, M4300, and GSM7328FS stacked

HenryP22,

Welcome to the community! :) 

Every switch will need to have the following configuration on them:

1. IGMP Snooping enabled globally.
2. IGMP VLAN Configuration, each VLAN with Multicast needs to have admin mode enabled.
3.  At least 1 switch needs to be configured for IGMP Snooping Querier.  If having more make sure the core has the lowest IP Address assigned to it.
4. Enable IGMP Snooping Querier on each VLAN.

Here are the notes to remember:

 
1. IGMP snooping without IGMP-Plus (this feature is only available on M4300/M4250 switches) will flood ALL multicast traffic between switches (sometimes even re-broadcasting back up to the original switch that sent the data).  This can quickly saturate links.
2. Stacking doesn’t handle multicast traffic well.
3. Make sure Multicast traffic is distributed as much as possible not to have same MAC address. (32 Multicast addresses to each MAC address)
4. Make sure LAG Hash set to include DEST IP address (Hash modes 5/6/7) to allow for better balancing over LAG.

Furthermore, if you REALLY wanted to do this right, you should swap to M4300 cores with M4250 switches replacing all the M4100 switches.  It is costly, but more efficient and cleaner.

Regards,

DaneA

NETGEAR Community Team