From owner-freebsd-net@FreeBSD.ORG Wed Mar 12 21:22:42 2008 Return-Path: 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 04E5E106566B for ; Wed, 12 Mar 2008 21:22:42 +0000 (UTC) (envelope-from auryn@zirakzigil.org) Received: from aurynhome1sv1.zirakzigil.org (mail.zirakzigil.org [82.63.178.63]) by mx1.freebsd.org (Postfix) with SMTP id 394AF8FC16 for ; Wed, 12 Mar 2008 21:22:40 +0000 (UTC) (envelope-from auryn@zirakzigil.org) Received: (qmail 55016 invoked by uid 98); 12 Mar 2008 21:22:39 -0000 Received: from 192.168.229.11 by aurynhome1sv1.zirakzigil.org (envelope-from , uid 89) with qmail-scanner-1.25 ( Clear:RC:1(192.168.229.11):. Processed in 0.04097 secs); 12 Mar 2008 21:22:39 -0000 X-Qmail-Scanner-Mail-From: auryn@zirakzigil.org via aurynhome1sv1.zirakzigil.org X-Qmail-Scanner: 1.25 (Clear:RC:1(192.168.229.11):. Processed in 0.04097 secs) Received: from unknown (HELO aurynhome1ws2.zirakzigil.org) (postmaster@zirakzigil.org@192.168.229.11) by 0 with SMTP; 12 Mar 2008 21:22:39 -0000 Message-ID: <47D8499A.5070605@zirakzigil.org> Date: Wed, 12 Mar 2008 22:22:34 +0100 From: Giulio Ferro User-Agent: Thunderbird 2.0.0.0 (X11/20070513) MIME-Version: 1.0 To: Sam Leffler References: <47D7C34E.8060805@zirakzigil.org> <47D817D2.9010306@errno.com> In-Reply-To: <47D817D2.9010306@errno.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org, Andrew Thompson Subject: Re: VLAN trunking and fragmentation X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Mar 2008 21:22:42 -0000 Sam Leffler wrote: > You failed to provide the output of ifconfig on your running system. > Be sure any checksum offload is disabled (should be by the bridge). > > Sam My bad. I switched off checksum offload in /etc/rc.conf like this: ifconfig_re0="inet 192.168.60.1 netmask 255.255.255.0 -rxcsum -txcsum" (same thing on the other machine) Now my ifconfig on PC #1 is : ----------------------------------------- # ifconfig re0 re0: flags=8843 metric 0 mtu 1500 options=98 ether 00:14:c1:40:c2:e8 inet 192.168.60.1 netmask 0xffffff00 broadcast 192.168.60.255 media: Ethernet autoselect (1000baseTX ) status: active # ifconfig vlan0 vlan0: flags=8843 metric 0 mtu 1500 ether 00:14:c1:40:c2:e8 inet 192.168.100.1 netmask 0xffffff00 broadcast 192.168.100.255 media: Ethernet autoselect (1000baseTX ) status: active vlan: 10 parent interface: re0 ----------------------------------------- on PC #2 : ----------------------------------------- # ifconfig re0 re0: flags=8843 metric 0 mtu 1500 options=98 ether 00:15:8a:00:48:80 inet 192.168.60.2 netmask 0xffffff00 broadcast 192.168.60.255 media: Ethernet autoselect (1000baseTX ) status: active # ifconfig vlan0 vlan0: flags=8843 metric 0 mtu 1500 ether 00:15:8a:00:48:80 inet 192.168.100.2 netmask 0xffffff00 broadcast 192.168.100.255 media: Ethernet autoselect (1000baseTX ) status: active vlan: 10 parent interface: re0 ----------------------------------------- Any packet greater than 1472 which gets fragmented doesn't pass through: command : ping -c 1 -s 1473 192.168.100.2 on the sending machine: ----------------------------------------- # tcpdump -i re0 -n -vvv not tcp and not stp 23:11:07.649600 IP (tos 0x0, ttl 64, id 399, offset 0, flags [+], proto ICMP (1), length 1500) 192.168.100.1 > 192.168.100.2: ICMP echo request, id 19972, seq 0, length 1480 23:11:07.649605 IP (tos 0x0, ttl 64, id 399, offset 1480, flags [none], proto ICMP (1), length 21) 192.168.100.1 > 192.168.100.2: icmp ----------------------------------------- Whereas on the receiving machine I don't get any packet. Thanks for your answer.