TTL/Hop Limit Issues in BFD for on a single hop
"Bhatia, Manav \(Manav\)" <manav@alcatel-lucent.com> Sun, 23 November 2008 01:33 UTC
Return-Path: <rtg-bfd-bounces@ietf.org>
X-Original-To: rtg-bfd-archive@megatron.ietf.org
Delivered-To: ietfarch-rtg-bfd-archive@core3.amsl.com
Received: from [127.0.0.1] (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 3DE703A6941; Sat, 22 Nov 2008 17:33:41 -0800 (PST)
X-Original-To: rtg-bfd@core3.amsl.com
Delivered-To: rtg-bfd@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 30A293A6941 for <rtg-bfd@core3.amsl.com>; Sat, 22 Nov 2008 17:33:40 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.599
X-Spam-Level:
X-Spam-Status: No, score=-2.599 tagged_above=-999 required=5 tests=[BAYES_00=-2.599]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Zg6IVI6uDxIv for <rtg-bfd@core3.amsl.com>; Sat, 22 Nov 2008 17:33:39 -0800 (PST)
Received: from ihemail4.lucent.com (ihemail4.lucent.com [135.245.0.39]) by core3.amsl.com (Postfix) with ESMTP id 6974C3A68FC for <rtg-bfd@ietf.org>; Sat, 22 Nov 2008 17:33:38 -0800 (PST)
Received: from ilexp01.ndc.lucent.com (h135-3-39-1.lucent.com [135.3.39.1]) by ihemail4.lucent.com (8.13.8/IER-o) with ESMTP id mAN1XYwo013193 for <rtg-bfd@ietf.org>; Sat, 22 Nov 2008 19:33:34 -0600 (CST)
Received: from inexp01.in.lucent.com ([135.254.223.65]) by ilexp01.ndc.lucent.com with Microsoft SMTPSVC(6.0.3790.1830); Sat, 22 Nov 2008 19:33:33 -0600
Received: from INEXC1U01.in.lucent.com ([135.254.223.25]) by inexp01.in.lucent.com with Microsoft SMTPSVC(6.0.3790.1830); Sun, 23 Nov 2008 07:03:29 +0530
X-MimeOLE: Produced By Microsoft Exchange V6.5
Content-class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: quoted-printable
Subject: TTL/Hop Limit Issues in BFD for on a single hop
Date: Sun, 23 Nov 2008 07:03:28 +0530
Message-ID: <6D26D1FE43A66F439F8109CDD424196502356386@INEXC1U01.in.lucent.com>
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
Thread-Topic: TTL/Hop Limit Issues in BFD for on a single hop
thread-index: AclNC3yoOURWhcuUTOKCHJDsTpV6KQ==
From: "Bhatia, Manav (Manav)" <manav@alcatel-lucent.com>
To: rtg-bfd@ietf.org
X-OriginalArrivalTime: 23 Nov 2008 01:33:29.0458 (UTC) FILETIME=[7D0A5D20:01C94D0B]
X-Scanned-By: MIMEDefang 2.57 on 135.245.2.39
X-BeenThere: rtg-bfd@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: "RTG Area: Bidirectional Forwarding Detection DT" <rtg-bfd.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/rtg-bfd>, <mailto:rtg-bfd-request@ietf.org?subject=unsubscribe>
List-Archive: <https://www.ietf.org/mailman/private/rtg-bfd>
List-Post: <mailto:rtg-bfd@ietf.org>
List-Help: <mailto:rtg-bfd-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtg-bfd>, <mailto:rtg-bfd-request@ietf.org?subject=subscribe>
Sender: rtg-bfd-bounces@ietf.org
Errors-To: rtg-bfd-bounces@ietf.org
Hi, This is wrt the text in Section 5 of draft-ietf-bfd-v4v6-1hop-08.txt. It states that that BFD Control packets for the session MUST be sent with a TTL or Hop Limit value of 255 irrespective of whether BFD auth is being used or not. Fair enough. Now why is it that when auth is being used the recover *MAY* (and not MUST) reject BFD control packets received with TTL/Hop Limit value other than 255? Why is it not a "MUST" the way it is for un-authenticated sessions? Second, the draft should unequivocally state that the sanity of TTL/Hop Limit MUST be checked first before the authentication data is verified. You don't want the receiver to compute the hash only to later drop the packet because the TTL/Hop limit was incorrect or not within the acceptable range. Cheers, Manav -- Manav Bhatia, IP Division, Alcatel-Lucent, Bangalore - India
- TTL/Hop Limit Issues in BFD for on a single hop Bhatia, Manav (Manav)
- Re: TTL/Hop Limit Issues in BFD for on a single h… Nitin Bahadur
- RE: TTL/Hop Limit Issues in BFD for on a single h… Bhatia, Manav (Manav)