From owner-freebsd-hackers@FreeBSD.ORG  Tue Jun 27 09:22:29 2006
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
X-Original-To: freebsd-hackers@freebsd.org
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 5C03F16A403
	for <freebsd-hackers@freebsd.org>; Tue, 27 Jun 2006 09:22:29 +0000 (UTC)
	(envelope-from yar@comp.chem.msu.su)
Received: from comp.chem.msu.su (comp.chem.msu.su [158.250.32.97])
	by mx1.FreeBSD.org (Postfix) with ESMTP id EB50943D64
	for <freebsd-hackers@freebsd.org>; Tue, 27 Jun 2006 09:22:25 +0000 (GMT)
	(envelope-from yar@comp.chem.msu.su)
Received: from comp.chem.msu.su (localhost [127.0.0.1])
	by comp.chem.msu.su (8.13.4/8.13.3) with ESMTP id k5R9M7ZV037963;
	Tue, 27 Jun 2006 13:22:07 +0400 (MSD)
	(envelope-from yar@comp.chem.msu.su)
Received: (from yar@localhost)
	by comp.chem.msu.su (8.13.4/8.13.3/Submit) id k5R9M1aA037958;
	Tue, 27 Jun 2006 13:22:01 +0400 (MSD) (envelope-from yar)
Date: Tue, 27 Jun 2006 13:22:01 +0400
From: Yar Tikhiy <yar@comp.chem.msu.su>
To: David Gilbert <dgilbert@dclg.ca>
Message-ID: <20060627092201.GC36941@comp.chem.msu.su>
References: <17560.50693.145833.875903@canoe.dclg.ca>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <17560.50693.145833.875903@canoe.dclg.ca>
User-Agent: Mutt/1.5.9i
Cc: freebsd-hackers@freebsd.org
Subject: Re: curious 6.1 GRE behaviour.
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 27 Jun 2006 09:22:29 -0000

On Wed, Jun 21, 2006 at 12:07:33AM -0400, David Gilbert wrote:
> I was using some GRE tunnels on 6.1-RELEASE recently.  The odd thing
> I'm finding is that the initial creation of the tunnel using
> cloned_interfaces and ifconfig_gre0="<blah>" results in the gre0
> interface being created without the "running" bit set.
> 
> tcpdump on the interface or even "ifconfig gre0 up" starts it.
> 
> This is also odd because the "UP" flag is set.  Ie:
> [1:2:301]root@pbx:~> ifconfig
> [...]
> gre0: flags=9011<UP,POINTOPOINT,LINK0,MULTICAST> mtu 1476
>         tunnel inet x.x.x.x --> y.y.y.y
>         inet6 fe80::240:63ff:fee2:eae9%gre0 prefixlen 64 scopeid 0x5 
>         inet a.a.a.a --> b.b.b.b netmask 0xfffffffe 
> [1:2:302]root@pbx:~> ifconfig gre0 up
> [1:3:303]root@pbx:~> ifconfig
> [...]
> gre0: flags=9051<UP,POINTOPOINT,RUNNING,LINK0,MULTICAST> mtu 1476
>         tunnel inet x.x.x.x --> y.y.y.y
>         inet6 fe80::240:63ff:fee2:eae9%gre0 prefixlen 64 scopeid 0x5 
>         inet a.a.a.a --> b.b.b.b netmask 0xfffffffe 

FWIW, gre(4) in CURRENT doesn't seem to have this problem.

However, it has a different one: the system will lose its default
route upon the destruction of a gre interface albeit the default
route is via a different interface.  Aha, it appears to be due to
the activity of /etc/pccard_ether, not gre(4) itself.  Looks like
a way of fast and easy foot-shooting unless one remembers to set
removable_route_flush to NO.  Are we drifting from the server/router
market to the desktop/mobile market?..

-- 
Yar