First let me apologize for this rather lengthy post, I have tried to condense the information the best I can. I am having problem setting up proper multicasting settings on the SLM series switches. The IGMP snooping doesn't seem to work as advertised/expected.
I've read the following threads, and it seems to have some similar veins but doesn't seem to address the SLM2024 issues I am seeing
No matter what I do, the 2024 seems to broadcast all multicast packets down every port. This doesn't seem to matter whether or not any hosts have asked to join a multicast group or not. Everyone gets everything. As you can see from the diagram below, that can result in quite a mess since each camera can use ~40+% of a GigE pipe.
The same thing occurs on the 2008 unless I turn off the option to broadcast unregistered multicast. But from what I see on wireshark, even multicast addresses with join requests are being flooded.
1. When multiple IGMP snooping switches are used as shown above, do the switches treat adjacent switches as "routers" as defined by rfc4541
2. The provider of a multicast stream may not be the one who joins the group first since it already has the data locally. If a stream starts up prior to anyone joining it, will the switch/es be smart enough to transition from treating the packets as unregistered multicast to treating them as registered ones?
An unregistered packet is defined as an IPv4 multicast packet with a destination address which does not match any of the groups announced in earlier IGMP Membership Reports.
3. So the way I read this is that once a group membership is received, the switch should cease flooding the packets associated with this membership and only forward them to the appropriate ports. Conversely I would also expect that should the last listener leave the group, the switch will begin to flood all ports with its data ... this sounds wrong.... Is that the case?
4. When looking at the port with Wireshark, I see a many join reports from other hosts.. Is this in conflict with rfc4541 2.1.1??
5. Is there a way to see what memberships groups the switch currently recognizes?
6. If 2 IGMP snooping switches are connected to each other, do they communicate so that only needed multicast packets pass between each other, Or will they forward all the packets? Two SLM2008 connected to each other appear to only forward the needed traffic, but if I connect the same 2008 to a 2024, it starts passing all the multicast to the 2024 without regard for the multicast joins. and the 2024 with flood each one of its ports with that traffic.
7. Pinging 184.108.40.206 should return the ip of all multicast capable hosts. when I try it, I end up getting multiple entries for the same IP/icmp_seq combo... I'm not sure what would cause this. Any thoughts?
8. Port mirroring on a port on a LAG doesn't seem to be allowed on the 2024 (even though it is allowed on the 2008).. The LAG isn't an option in the pulldown either. Am I doing something wrong?
Some side notes that maybe helpful:
1. I've tried both the 1.0.1 and the 220.127.116.11 version of the SLM2024 and I can't seem to get it to work.
2. The SLM2008 webgui is significantly different for the SLM2024 ( MUCH easier to setup/use and debugwith . Kudos to that development team)
The Status page is extremely useful, and I hope that it transitions over to the 2024 at some point. It also works with any browser as opposed to the
2024 that requires firefox or IE/activex etc.
3. I have IGMP snooping turned on all switches. All SLM2008 additionally have the option to broadcast unregistered multicast disabled.