Subject: remove

From: Les Stuart <[email-masked]>
Date: Fri, 27 Apr 2001 08:21:28 -0700

Please remove me from this list

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Thursday, April 26, 2001 5:55 PM
To: [email-masked]; Isidor Kouvelas
Subject: Re: Another IGMPv3 question

From:  James Huang@MITEL on 04/26/2001 05:54 PM PDT
Hi Isidor:

     I found the the following quote from an email you sent back in
Aug/2000.

"When the last host in EXCLUDE mode leaves the group, the router sends a
group
specific query. This causes the EXCLUDE group timer on the router to be
lowered.
At this point all hosts in INCLUDE mode respond and update the list X. As
there
are no hosts left in EXCLUDE mode, no EXCLUDE reports are received to update
the
group timer. Hence the timer expires with all the sources in INCLUDE mode
listed
in X. At this point list X is used as the list of source to forward in
INCLUDE
mode."

     I believe what you described there is about the action to take when
receiving a TO_IN(A) report when in the EXCLUDE(X,Y) state. My question is
whether the router should also send a qroup-specific query when the group
timer
expires and the router is about to switch from the EXCLUDE mode to the
INCLUDE
mode. When I read section 6.5 "Switching Router Filter-Modes", I can not
find
any description about sending a group specific query when the group timer
expires.  Without sending a group-sepcific query before switching the filter
mode of the group, you may end up not forwarding traffics from some sources
which have interested receivers in the subnet. This may happen, for example,
when the last EXCLUDE mode host crashes. Of course, the router only have to
send
the group-specific query if it has not sent such query recently.  Otherwise,
the
router will keep on sending group-specific queries.

Thanks,
-- James Huang