From owner-freebsd-questions@FreeBSD.ORG Wed May 19 19:22:02 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id ED671106566C for ; Wed, 19 May 2010 19:22:02 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from asmtpout024.mac.com (asmtpout024.mac.com [17.148.16.99]) by mx1.freebsd.org (Postfix) with ESMTP id DBF3C8FC1B for ; Wed, 19 May 2010 19:22:02 +0000 (UTC) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; charset=us-ascii Received: from cswiger1.apple.com ([17.209.4.71]) by asmtp024.mac.com (Sun Java(tm) System Messaging Server 6.3-8.01 (built Dec 16 2008; 32bit)) with ESMTPSA id <0L2O00ELSLSMHN30@asmtp024.mac.com> for freebsd-questions@freebsd.org; Wed, 19 May 2010 12:21:59 -0700 (PDT) From: Chuck Swiger In-reply-to: Date: Wed, 19 May 2010 12:21:58 -0700 Message-id: References: To: Marco Beishuizen X-Mailer: Apple Mail (2.1078) Cc: freebsd-questions@freebsd.org Subject: Re: downloading e-mail is blocking network X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 May 2010 19:22:03 -0000 Hi, Marco-- On May 19, 2010, at 12:15 PM, Marco Beishuizen wrote: > I'm having a strange network problem. Every day, when I turn on my computer, fetchmail is started and procmail is putting all my mail in the correct mailboxes. This takes some time because I receive a few hundred e-mails a day (mostly mailing lists). > > The strange thing is that when the e-mail is being downloaded, all other network traffic seems blocked. So browsing the internet is not possible when fetchmail/procmail is busy. At first I thought I had a problem with DNS and/or DHCP and/or my ADSL modem because after a reset of the modem, the problem mostly went away, and there were some "hostname not found" errors in my logfiles. But today I just waited for a while and discovered that when fetchmail/procmail is finished, the internet suddenly was reachable again. > > So has anyone has seen fetchmail/procmail blocking network traffic before? Are you using NAT? It sounds like something has a limited number of NAT state slots available, and is dropping connections past that limit. It probably will help to try to serialize the activity of fetchmail / procmail so that they aren't opening new connections for every email being processed, if that is what is going on. Regards, -- -Chuck