Subject: IGMP query

From: [email-masked]
Date: Wed, 24 May 2000 12:50:47 +0100

Hi Mr Fenner and IDMR people,
I am an editor at SmartForce, the computer-based learning company, and
obtained your e-mail addresses from RFC 2236.
I would be very grateful if you could answer or assist with this query on
'stranded groups' in IGMP, which I can't find covered in the relevant RFCs
or Cisco documents.
The passage I am editing describes how IGMP deals with topology changes
such as 'disappearing endpoints and stranded groups'.
There is no problem about disappearing endpoints-- it is clear from the
context what happens here, but no description of a stranded group is
available.  I and my technical advisor both think it means a group whose
remote connection goes down, with the result that the creator node receives
no confirm responses from the stranded group and deletes it.
Can you confirm this-- and even better, can you indicate whether IGMP
provides an automatic mechanism for restoring such a group (assuming of
course that it is physically possible), or whether IGMP breaks down in such
a case.
Regards
Paul Nash