Subject: (*,G) state in PIM-DM

From: Alejandro Avella <[email-masked]>
Date: Sun, 15 Nov 1998 20:47:07 -0700

Hi everyone,

PIM-DM only uses source trees (no shared trees are used).  However, in
PIM-DM,
(*,G) entries are created automatically as soon as the first packet
(from any source)
arrives for group "G" or when a locally connected host has joined the
group via IGMP.  [1]

Question: I think there is no need to create this (*,G) entry.  It seems

like a duplicate entry in the table that is not needed.  Is this
correct?
If not, what is the purpose of the (*,G) entry?

(*,G) entries are used  in sparse mode to create shared trees,
but it does not make sense to me to have this entry in dense mode (I
think).

Cheers,

-Alejandro

[1] ftp://ftp-eng.cisco.com/ipmulticast/training/Module3.pdf