Month: March 2011

Configuring IP Multicast in Sparse-mode with Auto-RP

Goal: Multicast across VLANs and across Layer 3 hops to other campus locations and verify shared-tree stream to the Rendezvous Point (RP).

Below is a diagram and basic configuration I used for sparse-mode multicasting utilizing auto-rp. I chose sparse-mode because of performance and scalability reasons for my one-to-many multicasting needs (streaming live events from a few sources).

I’m using the 6500 in Site A as my sole RP in this setup, strictly for simplicity. (FYI, the 6500 is actually a VSS cluster). Site B and Site C are over a MetroE connection across geographically diverse locations.

IGMP snooping is usually enabled by default on Cisco switches, but I have it disabled on the network, only allowing IGMP snooping on specified VLANs.

I used VLC to test multicasting, streaming source as rtp:// with a TTL of 6.

NOTE: I had to modify the global VLC settings on my source PC to get this to work. Do not forget to do this if testing with VLC! This mod can be found in VLC Preferences > Stream Output > Access Output > Hop Limit.