IGMP Snooping Not Working [WS-6-MINI]

[uberdome]

It doesn't quite work as expected yet. It now functions with a work-around, but not in a typical fashion. It is my understanding that IGMP snooping functionality is separate from IGMP querying functionality. Sometimes, both are needed (when you don't already have a querier in the system), but it is not necessarily better to have more.

I tested the above test layout with a UniFi switch with snooping enabled (no querier running) and with a Netgear switch with snooping enabled (no querier running). Both worked correctly right away, and neither needed an IP address on the VLAN network.

For the Netonix, enabling just snooping does not seem to run any snooping. Enabling the querier on the necessary VLAN starts running snooping but seemingly requiring a querier. It uses the primary Netonix IP for the querier if one is not configured for the VLAN. That configuration fails and blocks all IGMP traffic. If an IP is then set on the VLAN that fits the subnet, it works (but this behavior seems incorrect, and is not in keeping with how other switches run snooping). It appears to have the querier running at first, but after some time it switches to "idle" as seen using the "show igmp" command.

Any thoughts?

[Dave]

I will discuss with Eric tomorrow...

[Eric Stern]

If multiple queriers are running on the same network then the querier with the lowest IP address remains active and the other queriers go into an Idle state. When you do "show igmp" it will show the IP address of the Active Querier.

[uberdome]

If multiple queriers are running on the same network then the querier with the lowest IP address remains active and the other queriers go into an Idle state. When you do "show igmp" it will show the IP address of the Active Querier.

That is how a querier is selected when there are multiples. It appears the Netonix somehow needs to be configured as a querier in order to work, rather than just working with the existing querier on the network (as other switches do).

I'll do some more testing, but I think setting up snooping and setting up a querier should be separate options like they are on other systems.

[uberdome]

Ok, I did some further testing.

The way it currently functions (which I think is not standard as stated above, but explained here for troubleshooting), for IGMP snooping to work on any VLAN, that VLAN must have a valid IP address in the subnet running on that VLAN. It then will correctly identify the primary IGMP querier on the VLAN and switch its own querier to an idle state. Snooping does appear to work well when this is configured.

Now that I understand this limitation, I downgraded to 1.4.8rc10, and tested again. It worked the same way. I'm not sure what enabling "IGMP proxy" in rc11 did functionally, but since it is a routing protocol, I'm inclined to suggest it may not have offered improvements and may not be useful. Of course, the CLI option "show igmp" is very useful, so please keep that available.

Please let me know if you need any further information.

[Kingsley]

IGMP Snooping is still broken and not working, we have a network of 25 switches (mostly 8,12,26 port DC swiches) all running 1.4.8rc12 and if I start a multicast, it goes right throughout the network when nothing is requesting it. We have multiple VLAN's configured on the switches, multicast on is a dedicated camera VLAN and everywhere this vlan exists, multicast goes. IGMP snooping is enabled on every switch.

Can we expect a fix for this any time soon please?

Regards
Travis

[Eric Stern]

It works in my test lab. If you can provide me with details of a specific configuration that does not work I can look into it.

[uberdome]

It works in my test lab. If you can provide me with details of a specific configuration that does not work I can look into it.

Eric,

Have you had a chance to review my last post where it shows an IP is needed for IGMP snooping to work (this is not typical with other vendors)?

Thank you, Chris

[Kingsley]

My test lab is a default switch, IGMP snooping enabled, port 1 is 48v PoE to run a camera that is set to multicast to 226.2.242.123:60001 and any port i bring up the Ethernet carrier on receives the multicast. I've tested this with rc9, 10, 11 and 12. I've confirmed this with wireshark also. Nothing I do stops the multicast getting through.

I have also tested in our production environment and see the same thing. Multicast goes everywhere that vlan is configured.

Regards
Travis

[Eric Stern]

It works in my test lab. If you can provide me with details of a specific configuration that does not work I can look into it.

Eric,

Have you had a chance to review my last post where it shows an IP is needed for IGMP snooping to work (this is not typical with other vendors)?

Thank you, Chris

I don't see how that could be true. IGMP is a IP level protocol, therefore for the IGMP querier to work it would need to have a valid IP on the given VLAN. I could see IGMP snooping working with no IP address configured, but not with the querier option enabled.