All things related to multicast

["Marshall Eubanks" <>]

On Wed, 20 Aug 2003 10:57:52 +0100
 Luís Marta 
<>
 wrote:
> 
> ----- Original Message ----- 
> From: "Leonard Giuliano" 
> <>
> Sent: Tuesday, August 19, 2003 7:50 PM
> 
> >The better question may be why do you want incongruence in the first
> >place?  If you are going through the trouble of creating these p2p VLANs,
> >why not let unicast use them?  You might be better off creating this
> >topology and letting unicast and mcast flow congruently through it.
> 
> Thanks for everyone's anwers.
> 
> I have many unicast vlans, but i only want one mcast vlan. At any point, the
> chosen path by OSPF (and therefore PIM) is the unicast vlan interface, and
> the only way for me to make mcast traffic go through the right vlan is to
> use static mroutes, right?
> Unfortunately i don't think IOS and JUNOS implement MISIS...
> 
> Does the PIM Snooping mechanism on Foundry switches work well among
> different vendors routers? I mean, does it really work? :)
> 

If you only have one multicast VLAN, then  I think that you have to use a 
PIM snooping switch or accept flooding. 

The Foundry that I am familiar with only did (S,*)
snooping (i.e., if you want one multicast from a specific address, you will 
get all multicast from that address. (This may make more sense for
an interdomain switch than for your case, as it may mean that (*,G) traffic
may have to go through the unicast vlans.

I also notice that the HP 9300m Procurve switch router supports "PIM snooping
mode support" in routed 100/1000-T networks.

www.hp.com/rnd/pdfs/9300m_datasheet.pdf 

I know nothing about it more than this pdf.

Another solution might be to put a router at both ends of the VLAN. After all,
these snooping switches are just emulating a PIM router and it might be 
cheaper
to buy two cheap routers than one expensive switch.

Regards
Marshall 


> Luís Marta.
> ---------------
> FCCN-WAN
>