Subject: IGMPv3

From: Srivatsan S <[email-masked]>
Date: Tue, 12 Mar 2002 19:18:42 +0530

Hi,

Quoting from the igmpv3 draft:
From Section 3.2 regarding Interface State:

o if *any* such record has a filter mode of EXCLUDE, then the filter
  mode of the interface record is EXCLUDE, and the source list of the
  interface record is the intersection of the source lists of all socket
  records in EXCLUDE mode, minus those source addresses that appear in
  any socket record in INCLUDE mode.  For example, if the socket records
  for multicast address m on interface i are:

            from socket s1:  ( i, m, EXCLUDE, {a, b, c, d} )
            from socket s2:  ( i, m, EXCLUDE, {b, c, d, e} )
            from socket s3:  ( i, m, INCLUDE, {d, e, f} )

  then the corresponding interface record on interface i is:

                             ( m, EXCLUDE, {b, c} )

     I think the above condition for sockets in EXCLUDE mode will 
hold good if and only if the sources for s1 and s2 are completely 
blocked. If source timer is running on any of the sources 'b' or 
'c', I think this is not valid. The intersection of source lists
of all socket records in EXCLUDE mode works only for all blocked 
sources. I think this point is not clear in the draft.

Thanks,
Srivatsan

-- 
Srivatsan S
Email: [email-masked]
Phone: 91-80-8520261 Extn 6506
Bangalore, India.

---

From: Haixiang He <[email-masked]>
Date: Tue, 12 Mar 2002 11:01:32 -0500

> sources. I think this point is not clear in the draft.

The "source record" and "source timer" are only used in the IGMPv3 router
portion. From an IGMPv3 host socket point of view, there is no "source
timer" that associates a source. Also "source timer" is not used in a host's
interface record.

In IGMP Proxying, the upstream IGMP host interface record is computed
according to the downstream IGMP router interface records that contain the
"source timer". As I described in my last email, we should clarify this
issue in the IGMP Proxying draft.

Haixiang