Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
New Member

Multicast and Failover Teamed NICs has this issue.

Has anyone seen such a request from a customer although the request has nothing to do with the switches:

Windows 2000 client with two NIC cards in a Teamed configuration has one NIC connected to one CAT 6500 and the other to the another CAT6500. The NICs are configured in Failover Mode and not in Load Balaned Mode. So when one NIC fails the other takes over.

When I pull the cable from one NIC to it's CAT6500, unicast fails over almost immediately to the other NIC connecting to the other CAT 6500 and unicast starts to work. But Multicast will not work over the 2nd NIC until the client sends an IGMP JOIN Message over the 2nd NIC. The way the code is written on clients is that the IGMP Join Messages are only sent by the clients every 120 seconds and this is per the RFC requiremnt for a client to send JOIN every 120 seconds. This is 120 seconds even if the first NIC has failed.

Customers are expecting that the client - on occassions when the NIC fails - should send a JOIN message immediatley so that the 2nd switch IGMP snoops the packet and multicast resumes immediately and not after 6o or 120 seconds.

I am just curious to know if anyone else has recieved this request from other customers. Of course it is nothing to do with switches, but it is to do with Microsoft / NIC Driver / TCP Stack Implementation for Multicast on the Client.

Has anyone seen a code using WMI (Windows Management Interface) being written on the server where a NIC failure event in the Windows Event Logger being used to send a Multicast Join through the 2nd NIC so that the 2nd switch IGMP snoops the Join Request and sends multicast to that switch port.

New Member

Re: Multicast and Failover Teamed NICs has this issue.

Sorry - in the previous entry - I meant to say Multicast Report and everywhere I said Multicast Join. So please read JOIN as REPORT.

CreatePlease to create content