From owner-freebsd-stable@FreeBSD.ORG Sun Apr 24 22:39:17 2005 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 614C916A4CE for ; Sun, 24 Apr 2005 22:39:17 +0000 (GMT) Received: from pandora.afflictions.org (asylum.afflictions.org [64.7.134.90]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7B12343D31 for ; Sun, 24 Apr 2005 22:39:16 +0000 (GMT) (envelope-from dgerow@afflictions.org) Received: from localhost (localhost [127.0.0.1]) by pandora.afflictions.org (Postfix) with ESMTP id 4C8A778C64 for ; Sun, 24 Apr 2005 18:41:05 -0400 (EDT) Received: from pandora.afflictions.org ([127.0.0.1]) by localhost (pandora.afflictions.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 22886-05 for ; Sun, 24 Apr 2005 18:41:00 -0400 (EDT) Received: from dementia.afflictions.org (dementia.afflictions.org [172.19.206.56]) by pandora.afflictions.org (Postfix) with ESMTP id 5C5FF78C35 for ; Sun, 24 Apr 2005 18:41:00 -0400 (EDT) Received: by dementia.afflictions.org (Postfix, from userid 1001) id 2B3BF33C60; Sun, 24 Apr 2005 18:39:42 -0400 (EDT) Date: Sun, 24 Apr 2005 18:39:41 -0400 From: Damian Gerow To: stable@freebsd.org Message-ID: <20050424223941.GN720@afflictions.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-GPG-Fingerprint: B3D7 D901 A53A 1A99 BFD6 E6DF 9F3B 742B C288 9CC9 User-Agent: Mutt/1.5.9i X-Virus-Scanned: amavisd-new at pandora.afflictions.org Subject: TXCSUM on bge0 breaks bridging X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 24 Apr 2005 22:39:17 -0000 Someone just helped me through a bridging problem I was having, and I thought I'd throw the problem out to the list to see if it's a bug, or at least, for archival purposes. I have a machine that I'm using as a workstation, that I would also like to use to bridge a home LAN. It has two interfaces: bge and fxp. bge0 -> 172.19.206.56 fxp0 -> ipless When I bridged the two interfaces, the workstation could only talk on the bge side of the network, not the fxp side. Note that any device on either side of the network could speak to the other side. Some initial debugging: # sysctl net.link.ether.bridge net.link.ether.bridge.version: 031224 net.link.ether.bridge.debug: 0 net.link.ether.bridge.ipf: 0 net.link.ether.bridge.ipfw: 0 net.link.ether.bridge.copy: 0 net.link.ether.bridge.ipfw_drop: 0 net.link.ether.bridge.ipfw_collisions: 0 net.link.ether.bridge.packets: 2687590 net.link.ether.bridge.dropped: 0 net.link.ether.bridge.predict: 70 net.link.ether.bridge.enable: 1 net.link.ether.bridge.config: fxp0 bge0 # I tcpdump'ed on the fxp interface, and could see a device nab an address via DHCP, and an ARP to the device from my workstation seemed to work, but I could not ping it. It was pointed out to me that the fxp does off-board checksumming, and what would happen if I disabled the one on bge0? Well, it fixed the problem. I can have TXCSUM enabled *only* on fxp0, not on bge0: so long as TXCSUM is disabled on bge0, irregardless of the state of fxp0, I can talk to any device attached to fxp0.