Hello, I working in an environment that has its own seperate network. The network consists of several Cisco 3750 switches. The network also has some devices on it that send out Multicast traffic. We want to limit these multicasts from broadcasting throughout the isolated network.
I know that IGMP snooping is enabled by default on the switches but the problem I run into is getting a IGMP Querier configured. Because at the moment, I do not see the devices sending out Multicast traffic joining a IGMP group, instead its broadcasting everywhere. So IGMP snooping does not seem to be working properly.
Everything that I found so far requires either a Cisco router or a Cisco 65xx+ switch to be configured as the querier. Is it possible to setup IGMP snooping properly on this isolated network without needing a router or 65xx series switch? And if so, what command would I need to configure and would it only need to be configured on one switch or all switches.
Thank you
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We have some RFID scanners that are doing multicast and the individual in charge of the systems on that network are complaining of slow speeds when they are only using like 2% of the network. The vendor of the product told them to use IGMP snooping so they are pressuring us to set it up.
When I go to look at the IGMP snooping status, I do not see any groups formed so thats why I assumed we needed a IGMP qurier. .
I am assuming that the IGMP Snnoping status showed "enabled".
I don't think IGMP Snooping is your problem. Especially if you don't see any multicast groups on that VLAN.
I would look for something else causing the slowdown.
You should be able to monitor port utilization on that switch.
Another option would be to connect a sniffer to analyze the switchport they are reporting is slow and see what you get.
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by: kdearingPosted on 2008-05-03 at 06:08:05ID: 21492194
IGMP is a layer 2 protocol. Therefore any multicast sent out is available on that VLAN.
What IGMP Snooping does is to keep the multicast traffic from flooding all the VLAN ports. Only those ports "joining" the multicast group receive the traffic.
IGMP Snooping should be globally enabled by default.
To check the status of IGMP Snooping on your switches, issue the command "show ip igmp snooping".
Unsure why you believe you need to configure a IGMP Querier. That is only used in routing multicast traffic (Layer 3).
What specific problem are you having?