From owner-freebsd-net@freebsd.org  Wed Feb  1 14:33:18 2017
Return-Path: <owner-freebsd-net@freebsd.org>
Delivered-To: freebsd-net@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 60A38CCB0E6
 for <freebsd-net@mailman.ysv.freebsd.org>;
 Wed,  1 Feb 2017 14:33:18 +0000 (UTC)
 (envelope-from vangyzen@FreeBSD.org)
Received: from smtp.vangyzen.net (hotblack.vangyzen.net
 [IPv6:2607:fc50:1000:7400:216:3eff:fe72:314f])
 by mx1.freebsd.org (Postfix) with ESMTP id 4CD99BBA
 for <freebsd-net@freebsd.org>; Wed,  1 Feb 2017 14:33:18 +0000 (UTC)
 (envelope-from vangyzen@FreeBSD.org)
Received: from ford.home.vangyzen.net (unknown [76.164.15.242])
 by smtp.vangyzen.net (Postfix) with ESMTPSA id B551F56469;
 Wed,  1 Feb 2017 08:33:17 -0600 (CST)
Subject: Re: 11-stable mountd listens on port 993
To: Peter Blok <pblok@bsd4all.org>, freebsd-net@freebsd.org
References: <33C2BACA-E500-4C57-9827-797F5206C572@bsd4all.org>
From: Eric van Gyzen <vangyzen@FreeBSD.org>
Message-ID: <aeda2524-f36d-8680-ca4d-082d4c0e36a4@FreeBSD.org>
Date: Wed, 1 Feb 2017 08:33:14 -0600
User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:45.0) Gecko/20100101
 Thunderbird/45.6.0
MIME-Version: 1.0
In-Reply-To: <33C2BACA-E500-4C57-9827-797F5206C572@bsd4all.org>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-net>,
 <mailto:freebsd-net-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net/>
List-Post: <mailto:freebsd-net@freebsd.org>
List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-net>,
 <mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 01 Feb 2017 14:33:18 -0000

On 02/01/2017 06:28, Peter Blok wrote:
> I just updated to 11-stable@313042 and when I rebootted my system dovecot
> didn’t want to start because port 993 was already in use.
>
> Checked with lsof and it was mountd that was listening on this port. When I
> stopped mountd and started dovecot everything was fine. When I started mountd
> after this it worked ok.
>
> Next reboot everything was fine.
>
> Anybody know why mountd could have been listening to port 993?

Since mountd uses bindresvport_sa(3), the kernel chooses a port in the "low" 
range, configured via sysctl:

	net.inet.ip.portrange.lowlast: 600
	net.inet.ip.portrange.lowfirst: 1023

There is some randomness in the algorithm, so there is roughly a 1/424 chance of 
conflict.  You might use the -p flag to mountd or reduce lowfirst below 993.

Cheers,

Eric