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New Member

Multicast on a 3550 -48 SMI

Is there something special that needs to be done in order to enable multicast to work on a 3550. The connection works prior to starting the multicast, the clients and server are on the same layer 2 network, and the clients and server are connected to the same 3550... THis is my first 3550.

Any help is appreciated.

Cisco Employee

Re: Multicast on a 3550 -48 SMI

There is not enough detail here for anyone to offer any good advice.

Please offer more details on the application, what happens when the mcast starts flowing, what your config is (is IGMP snooping enabled, do you have a multicast router, etc).

New Member

Re: Multicast on a 3550 -48 SMI

I will witness the failure today but I can tell you all the traffic is local to that switch and that vlan, we do not have multicast enabled on the router, the traffic does not need to go beyond....

I am not too familiar with the product and how it works except from what they tell me. They are using a product Ghost... where the clients register with a console this console machine acts like the server and this console machine has an image that will be sent to all those registered clients in a multicast format. All the switch ports on the 3550 are set to be in the same vlan, and as I said on the same 3550... I am wondering if there is something defaulted at the switch level that if it sees a multicast packet it will not forward it unless "x" is turned on. We have successfully repeated this procedure numerous times prior on 3548's, 2948's, and 1924's without any failures...

I hope to have more info later this morning.

Thanks for the help.

New Member

Re: Multicast on a 3550 -48 SMI

You shall know that there will be a braodcast flow if there is no a multicast router. Cisco's Multicast works as follow as:

1¡¢router send a query to switch for multicast group member

2¡¢The switch in which there are multicast group member give a reply to router

3¡¢then router will forward the data to the correspond switch.

If router don't enable multicast protocol,the multicast can't be used in different subnet

if switch don't enable multicast protocol,there will be s broadcast storm in switch

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