VLAN Interface Multicast ACL Problem

[Amtiskaw]

Hiya

We want to allow L3 multicast traffic between two vlans (one /24 per vlan) but block L3 multicast from these two VLANs to any other subnet.

An easy way would be to put a deny where source address is either of the two subnets, on all vlan interfaces except the two that need to talk. But then we have to apply that ACL to a bunch of VLAN interfaces. Being the lazy, absent-minded admin that I am, is there a way to put an ACL on just the two vlan interfaces that we want to isolate?

I can't see how, as the destination address in an ACL is going to be the multicast address.

Cheers

Simon