All things related to multicast

["Marshall Eubanks" <>]

On Tue, 19 Aug 2003 13:53:28 -0400
 Alan Crosswell 
<>
 wrote:
> Perhaps you could set up GRE tunnels across your infrastructure and only
> enable 
> PIM on the tunnels?  Cisco actually recommends this technique as a way to
> load 
> share multicast across parallel links (letting the underlying unicast 
> routing
> protocol to the load sharing).
> /a
> 

This is exactly the problem that Bill Nickless faces at Star-tap, and
I believe he uses vlan's.

You could also explore getting a Foundry swith with PIM snooping.

> Luís Marta wrote:
> > Hi.
> > 
> > If one has a backbone network based on Fast/Gigabit Ethernet, different
> > brands of routers and not-so-powerful switches (no chance of running 
> > RGMP),
> > how does one implement multicast?
> > In order to avoid the multicast traffic to leak to all the switches' 
> > ports,
> > i thought of creating a separate VLAN to the multicast traffic, a VLAN 
> > that
> > connects the RP, the backbone routers until the last one before the client
> > (the access routers), but then the last connection may be ATM ou any other
> > technology.

I think you will need one tunnel per multicast path.

> > As PIM interacts with the routing protocol in use (OSPF for example), how
> > can i make the multicast traffic that is supposed to go to a certain 
> > client
> > use the mentioned VLAN? Is there any other way of doing this without using
> > static mroutes to map the clients' routes? Because this is very
> > time-consuming and impossible to maintain.

BGP could do this if each tunnel is between autonomous systems.

> > 
> > Thanks in advance,
> > 
> > Luís Marta.
> 

Regards
Marshall