Multicast Routing - Part IV Limiting Bandwith Part I

Following on from Multicast Routing Part III i now look at how multicast streams can be controlled to limit bandwidth utilisation.

For multicast streams 227.20.20.20 i implement a policy that limits bandwidth consumption to 100k.

First i define my acl.

access-list 20 permit 227.20.20.20

Then i make use of the rate-limit function to control this streams network utilisation

#int fa0/0
config-if# ip multicast rate-limit out group-list 20 out

To prevent unnecessary bandwidth utilisation caused by multicast feeds looping around the network i can also set a multicast ttl threshold on the interface. For example to ensure no multicasts are sent when there ttl drops below 10 i can enter the following command.

#int fa0/0
config-if#ip multicast rate-limit 9