Catalyst 3550 and unidirectional multicast

[emil_slavov]

I have several segments routed by several Catalysts 3550. In one of the segments i start multicast TV streamer. I use IGMP and PIM to route the multicast. But how to restrict the clients only to receive multicast TV stream not to send multicast traffic to other segments joined the same group ?

[kumarapalani]

Hi,

I am not sure about what you are asking but you cld restrict the multicast traffic (say PIM ) by defining the boundary or the scope( TTL value is set to 0 after this point).

[Richard Burts]

Setting a boundary or setting scope will restrict all multicast traffic and preventing any local client from sending any multicast would also prevent forwarding the received multicast any further. Depending on the topology and what the processing requirements are this might or might not be a good solution.

Another alternative to consider is if you want to allow received multicast to be forwarded but want local originated multicast not to be forwarded would be to configure an outbound access list on the interface. In the access list would be a line like this:

deny ip 224.0.0.0 15.255.255.255

this will deny any packet with any broadcast destination address which has a source address within the local subnet. The acccess list would also have to have appropriate permit commands for the traffic that you do want to send (perhaps permit ip any any).

HTH

Rick