From owner-idmr@cs.ucl.ac.uk Tue Oct 14 06:23:14 2003 Received: from pan2.cs.ucl.ac.uk (pan2.cs.ucl.ac.uk [128.16.8.208]) by ietf.org (8.9.1a/8.9.1a) with SMTP id GAA02777 for ; Tue, 14 Oct 2003 06:23:13 -0400 (EDT) Received: from pan2.cs.ucl.ac.uk by pan2.cs.ucl.ac.uk via Local Delivery channel id ; Tue, 14 Oct 2003 10:39:11 +0100 Received: from bells.cs.ucl.ac.uk by pan2.cs.ucl.ac.uk with local SMTP id ; Tue, 14 Oct 2003 09:42:07 +0100 Received: from vscan-c.ucl.ac.uk by bells.cs.ucl.ac.uk with UK SMTP id ; Tue, 14 Oct 2003 09:42:58 +0100 Received: from mailserv.intranet.gr ([146.124.14.106]) by vscan-c.ucl.ac.uk with esmtp (Exim 4.20) id 1A9KlZ-0002hj-5Z for idmr@cs.ucl.ac.uk; Tue, 14 Oct 2003 09:42:53 +0100 Received: from mailserv.intranet.gr (localhost [127.0.0.1]) by mailserv.intranet.gr (8.11.7/8.11.3) with ESMTP id h9E8kda01090 for ; Tue, 14 Oct 2003 11:46:39 +0300 (EEST) Received: from aurora.intranet.gr (aurora.intranet.GR [146.124.34.195]) by mailserv.intranet.gr (8.11.7/8.11.3) with ESMTP id h9E8kbj01074; Tue, 14 Oct 2003 11:46:37 +0300 (EEST) Received: from pcrh184 (pcrh184 [146.124.34.101]) by aurora.intranet.gr (8.8.8+Sun/8.8.8) with SMTP id LAA17576; Tue, 14 Oct 2003 11:37:36 +0300 (EET DST) Message-ID: <009701c3922f$02201100$65227c92@intranet.gr> From: Theodoros Kallimanis To: idmr , fenner Subject: IGMP V2 (RFC2236) clarification Date: Tue, 14 Oct 2003 11:41:48 +0300 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0094_01C39248.26FAD820" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 X-UCL-MailScanner: Found to be clean X-UCL-MailScanner-SpamScore: s Sender: owner-idmr@cs.ucl.ac.uk Precedence: bulk This is a multi-part message in MIME format. ------=_NextPart_000_0094_01C39248.26FAD820 Content-Type: text/plain; charset="windows-1253" Content-Transfer-Encoding: quoted-printable Hello, I will appreciate a lot if you can clarify a point in IGMP V2 RFC 2236. = In the protocol description (ch. 3) the following phrase is mentioned: " When a host joins a multicast group, it should immediately transmit an = unsolicited Version 2 Membership Report for that group, in case it is = the first member of that group on the network" The phrase refers actually to the original join of the group by a = non-memebr host. The undelined part of the phrase is the part where I = need a clarification. How the "non-member" host can identify that it is = the first member of the group? At the state machine diagram at chapter 6 = / page 10, no reception of "join group" is shown at Non-Member state. = The text at chapter 3 indicates that the Membership Report is sent = immediately, so it is assumed that no response delay exists in the case = of the initial membership reports sending. Can you clarify please if = this is a valid point on the RFC and if it is how this is supposed to be = realized? Best Regards and thanks in advance for the assistance =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D Theodoros Kallimanis Systems and SW engineer INTRACOM SA Dept "Access & Transmission" tel : +30-210-6671961 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D ------=_NextPart_000_0094_01C39248.26FAD820 Content-Type: text/html; charset="windows-1253" Content-Transfer-Encoding: quoted-printable

Hello,

I will appreciate a lot if you can clarify a point = in IGMP V2=20 RFC 2236. In the protocol description (ch. 3) the following phrase is=20 mentioned:

" When a host joins a multicast group, = it should=20 immediately transmit an unsolicited Version 2 Membership Report for that = group,=20 in case it is the first member of that group on the=20 network"

The phrase refers actually to the original join of = the group=20 by a non-memebr host. The undelined part of the phrase is the part where = I need=20 a clarification. How the "non-member" host can identify that it is the = first=20 member of the group? At the state machine diagram at chapter 6 / = page 10,=20 no reception of "join group" is shown at Non-Member state. The text at = chapter 3=20 indicates that the Membership Report is sent immediately, so it is = assumed that=20 no response delay exists in the case of the initial membership reports = sending.=20 Can you clarify please if this is a valid point on the RFC and if it is = how this=20 is supposed to be realized?

Best Regards and thanks in advance for the=20 assistance

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
   =20 Theodoros Kallimanis
     Systems and SW=20 engineer
     INTRACOM = SA
    =20 Dept "Access & Transmission"
     tel :=20 +30-210-6671961
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

------=_NextPart_000_0094_01C39248.26FAD820-- From owner-idmr@cs.ucl.ac.uk Tue Oct 14 12:45:03 2003 Received: from pan2.cs.ucl.ac.uk (pan2.cs.ucl.ac.uk [128.16.8.208]) by ietf.org (8.9.1a/8.9.1a) with SMTP id MAA18713 for ; Tue, 14 Oct 2003 12:45:03 -0400 (EDT) Received: from pan2.cs.ucl.ac.uk by pan2.cs.ucl.ac.uk via Local Delivery channel id ; Tue, 14 Oct 2003 16:52:22 +0100 Received: from bells.cs.ucl.ac.uk by pan2.cs.ucl.ac.uk with local SMTP id ; Tue, 14 Oct 2003 16:52:19 +0100 Received: from vscan-c.ucl.ac.uk by bells.cs.ucl.ac.uk with UK SMTP id ; Tue, 14 Oct 2003 16:53:01 +0100 Received: from h-135-207-24-32.research.att.com ([135.207.24.32] helo=mailman.research.att.com) by vscan-c.ucl.ac.uk with esmtp (Exim 4.20) id 1A9RT6-0005u5-IE for idmr@cs.ucl.ac.uk; Tue, 14 Oct 2003 16:52:16 +0100 Received: from unixmail.research.att.com (unixmail.research.att.com [135.207.26.71]) by mailman.research.att.com (8.12.8/8.12.8) with ESMTP id h9EFmC84011541; Tue, 14 Oct 2003 11:48:12 -0400 Received: from windsor.research.att.com (windsor.research.att.com [135.207.26.46]) by unixmail.research.att.com (8.12.8+Sun/8.8.7) with ESMTP id h9EFoEZn012945; Tue, 14 Oct 2003 11:50:14 -0400 (EDT) From: Bill Fenner Received: (from fenner@localhost) by windsor.research.att.com (8.11.6+Sun/8.8.5) id h9EFqBe27283; Tue, 14 Oct 2003 08:52:11 -0700 (PDT) Message-Id: <200310141552.h9EFqBe27283@windsor.research.att.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII To: tks@intracom.gr Subject: Re: IGMP V2 (RFC2236) clarification Cc: idmr@cs.ucl.ac.uk Date: Tue, 14 Oct 2003 08:52:10 -0700 Versions: dmail (solaris) 2.5a/makemail 2.9d X-UCL-MailScanner: Found to be clean Sender: owner-idmr@cs.ucl.ac.uk Precedence: bulk Theodoros, The host transmits the unsolicited report immediately and unconditionally upon joining (the transition out of the bottom of the "Non-Member" state in the state machine you referenced). The "in case it is ..." phrase is meant to be justification, not a conditional. Bill