From owner-freebsd-net@FreeBSD.ORG  Sat May  2 12:50:03 2009
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 876A61065675
	for <freebsd-net@freebsd.org>; Sat,  2 May 2009 12:50:03 +0000 (UTC)
	(envelope-from lstewart@freebsd.org)
Received: from lauren.room52.net (lauren.room52.net [210.50.193.198])
	by mx1.freebsd.org (Postfix) with ESMTP id 00F178FC12
	for <freebsd-net@freebsd.org>; Sat,  2 May 2009 12:50:02 +0000 (UTC)
	(envelope-from lstewart@freebsd.org)
Received: from lstewart.caia.swin.edu.au (lstewart.caia.swin.edu.au
	[136.186.229.95]) (authenticated bits=0)
	by lauren.room52.net (8.14.3/8.14.3) with ESMTP id n42CG9BS043617
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO);
	Sat, 2 May 2009 22:16:10 +1000 (EST)
	(envelope-from lstewart@freebsd.org)
Message-ID: <49FC3984.8050609@freebsd.org>
Date: Sat, 02 May 2009 22:16:04 +1000
From: Lawrence Stewart <lstewart@freebsd.org>
User-Agent: Thunderbird 2.0.0.21 (X11/20090412)
MIME-Version: 1.0
To: Kevin Day <toasty@dragondata.com>
References: <00C19FCC-837A-44B8-A0C9-C56E3D02F8EF@dragondata.com>
In-Reply-To: <00C19FCC-837A-44B8-A0C9-C56E3D02F8EF@dragondata.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Spam-Status: No, score=-2.0 required=5.0 tests=AWL,BAYES_00,SPF_SOFTFAIL
	autolearn=disabled version=3.2.5
X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on lauren.room52.net
Cc: freebsd-net@freebsd.org
Subject: Re: Slow local TCP transfers on -CURRENT
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/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: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
	<mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 02 May 2009 12:50:03 -0000

Kevin Day wrote:
> 
> I've been seeing this for a few months now on -CURRENT. TCP transfers to 
> local IP addresses (but not 127.0.0.1) are incredibly slow.
> 
> Transfer from localhost:
> 
> # scp "root@127.0.0.1:/boot/kernel/kernel" .
> kernel                                                                          
> 100%   11MB  11.1MB/s   00:00
> 
> Appropriately fast.
> 
> 
> Transfer from an IP on a local interface:
> 
> # scp "root@216.14.96.4:/boot/kernel/kernel" .
> kernel                                                                            
> 0%   16KB  13.0KB/s   14:37 ETA
> 
> 
> The routes seem normal:
> 
> 
> # route get 127.0.0.1
>   route to: localhost
> destination: localhost
>  interface: lo0
>      flags: <UP,HOST,DONE,LOCAL>
> recvpipe  sendpipe  ssthresh  rtt,msec    mtu        weight    expire
>       0         0         0         0     16384         1         0
> 
> # route -n get 216.14.96.4
>   route to: 216.14.96.4
> destination: 216.14.96.0
>       mask: 255.255.255.128
>  interface: nfe0
>      flags: <UP,DONE>
> recvpipe  sendpipe  ssthresh  rtt,msec    mtu        weight    expire
>       0         0         0         0      1500         1         0
> 
> 
> nfe0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
>        options=19b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4>
>        ether 00:30:48:c6:dd:9c
>        inet 216.14.96.4 netmask 0xffffff80 broadcast 216.14.96.127
> 
> Takes 10-60 minutes to copy, stalling frequently during the transfer. 
> It's not limited to just scp either, all TCP transfers seem to stall 
> this way.
> 
> 
> 
> I don't believe I'm doing anything unusual, has anyone seen anything 
> like this?

Known fallout from the ARPv2 work I believe. As a workaround until it 
gets fixed:

route add -host (if-ip) -iface lo0 (note I haven't tested this myself)

(see the Jan 2009 freebsd-net@ thread "Bacula: VERY SLOW on SAME host" 
for some details).

Cheers,
Lawrence