Here is the scenario.
A 6509 at the core. Running layer 3. It uplinks (layer 2) to a switch (owned by the state which i believe is layer 3) and routes out to the external network/internet.
All other switches in this school are layer 2. Multicast DOES NOT WORK. Unless i do the following commands on my 6509
ip multicast routring
int vlan 1
ip pim dense-sparse mode
Then it works like a charm. Without that commmand multicast works nowhere. Not even to the switch the multicast server is plugged into. Can anyone explain why? I understood multicast to be similar to a broadcast when it is look at from layer 2. Any insight would be appreciated.