From owner-freebsd-questions Fri May 21 7:45: 6 1999 Delivered-To: freebsd-questions@freebsd.org Received: from pasha.anand.org (pasha.anand.org [199.103.176.41]) by hub.freebsd.org (Postfix) with SMTP id A27AE14D39 for ; Fri, 21 May 1999 07:44:53 -0700 (PDT) (envelope-from arb@anand.org) Received: (qmail 2281 invoked by uid 1001); 21 May 1999 14:38:15 -0000 Date: Fri, 21 May 1999 17:38:15 +0300 From: Anand Buddhdev To: freebsd-questions@freebsd.org Subject: Path MTU discovery on FBSD Message-ID: <19990521173815.B1722@africaonline.co.ke> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.4i Organisation: Africa Online Ltd, P O Box 63017, Nairobi, Kenya X-Phone: +254-2-243775 X-WWW-Homepage: http://www.anand.org Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Today one of the firewalls at my upstream provider started to block ICMP. I noticed that a lot of my email started slowing down. I got a lot of deferrals (I'm using qmail). I have heard that this can happen when Path MTU discovery fails becuase of ICMP blocks. Does FreeBSD 3.1-RELEASE do this? How could I actually diagnose that this is indeed happening. I know about tcpdump, but I'm not very familiar with the details of TCP/IP. any pointers will be appreciated. Thanks, -- System Administrator See complete headers for address, homepage and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message