From owner-freebsd-stable Wed Oct 2 18:21:52 2002 Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8A64F37B401 for ; Wed, 2 Oct 2002 18:21:50 -0700 (PDT) Received: from yellow.biolateral.com.au (yellow.biolateral.com.au [129.78.217.60]) by mx1.FreeBSD.org (Postfix) with ESMTP id AB6C943E42 for ; Wed, 2 Oct 2002 18:21:49 -0700 (PDT) (envelope-from tonym@biolateral.com.au) Received: from dt.home (localhost [127.0.0.1]) by yellow.biolateral.com.au (8.12.6/8.12.6) with ESMTP id g931LeVZ047369; Thu, 3 Oct 2002 11:21:41 +1000 (EST) (envelope-from tonym@dt.home) Received: (from tonym@localhost) by dt.home (8.12.6/8.12.6/Submit) id g931LZWv047336; Thu, 3 Oct 2002 11:21:35 +1000 (EST) (envelope-from tonym) Date: Thu, 3 Oct 2002 11:21:35 +1000 (EST) From: Tony Maher Message-Id: <200210030121.g931LZWv047336@dt.home> To: peter.jeremy@alcatel.com.au Subject: Re: 'losing' every second packet Cc: stable@FreeBSD.ORG In-Reply-To: <20021003003859.GN495@gsmx07.alcatel.com.au> Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Peter, > I'm also using Optus cable, but with -STABLE from about a week ago and > IPfilter rather than ipfw. (I found that ipfw+natd+keep-state didn't > work). Ok sounds like we are running almost identical release so its good to know there is an alternative. (BTW ipfw+natd+keep-state have been working fine for me for past 12 months until this last month) > I haven't seen this problem and can't suggest any obvious > cause within FreeBSD. It is possible that Optus have added something > to their firewall to 'discourage' incoming setup packets (to enforce > their "no servers" policy). Hard to see how this could be the case ... hmmm unless they added a 50% drop rate on a destination after observing some form of 'unlawful' behaviour. Not that I am running any servers (well except sshd and hosts.allow restricts it to just my work machines). Using ssh does not seem to trigger it. Starting nmap V. 3.00 ( www.insecure.org/nmap/ ) Interesting ports on gw.optus (210.49.XXX.XX): (The 1599 ports scanned but not shown below are in state: filtered) Port State Service 22/tcp open ssh 113/tcp closed auth No exact OS matches for host (If you know what OS is running on it, > All I can suggest is running tcpdump on your firewall and a remote > machine and studying the packet loss when you send various packets > between the machines (ping, UDP and TCP). This might identify where > (in which direction) the packet loss is occurring. Packet loss appears to be independent of protocol, see it with ping, ssh (tcp) and games (udp). But yes - with long weekend I should get some time for trawling thru packets :-) thanks! -- tonym To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message