All things related to multicast

["John M. Zwiebel" <>]

 ^ 
 ^ -----BEGIN PGP SIGNED MESSAGE-----
 ^ 
 ^ At 09:58 AM 2/16/2001 -0500, Roy D. Hockett wrote:
 ^ >         I am seeking practical advice on both RP with sparse mode, and 
gro
    up
 ^ >filtering.
 ^ >
 ^ >         Of those that have deployed multicast in enterprises 
enviorments, 
    how
 ^ >did you setup your RPs. I remember, someone, talking about using a
 ^ >private IP address on a loopback interface on each router. How has
 ^ >auto-RP worked for those cisco shops out there?
 ^ 
 ^ MSDP RPF rules are a lot simpler when the RP is on your primary BGP 
 ^ NLRI=Multicast speaker.  My experience has been that things are a lot 
 ^ easier when you use a loopback address on your border router as your RP 
 ^ address.  This RP address *MUST* be advertised in your BGP NLRI=Multicast 
 ^ announcement, as an RFC-1918 address will NOT work with MSDP.  Remember, 
 ^ MSDP RPF checks are on the address of the RP.

However, you _may_ want to use this command which replaces the RP
address with any address on your MSDP speaking router.  ie, it doesn't
have to be the same address you use as the RP address.

    [no] ip msdp originator-id <interface>
        Allows a MSDP speaker, which originates an SA message, to use the
        IP address associated with <interface> as the RP address in the SA
        message. If this command is used with the "ip msdp border" command,
        the originator-id address will be used.

You can find some addtional information at:
  ftp://ftp-eng.cisco.com/ipmulticast.html
  http://www.cisco.com/go/ipmulticast


The question of how best to set up your RPs inside of an enterprise
depends on what you are expecting of your multicast connectivity.
Most organizations can get by just fine with a single RP on the border
as Bill suggested.  However, if you are planning on doing a lot of
multicasting, you'll want to make things a bit more redundent.

 ^ 
 ^ We statically configure the RP address in all of our other routers.  But 
 ^ other people have had good luck with auto-RP.
 ^ 
 ^ See my web page
 ^ 
 ^   http://www-fp.mcs.anl.gov/~nickless/MBGP+PIMSM+MSDP_files/v3_document.htm
 ^ 
 ^ for an outline of how PIM-SM, MSDP, and BGP NLRI=Multicast work together.
 ^ 
 ^ 
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        John Zwiebel                       Phone: 408-526-5303
        Cisco Systems Inc.                 
        IP Multicast Group