From owner-freebsd-hackers Mon Dec 21 09:17:45 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id JAA21048 for freebsd-hackers-outgoing; Mon, 21 Dec 1998 09:17:45 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from foonly.scimitar.org (cr323989-a.yec1.on.wave.home.com [24.112.82.27]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id JAA21006; Mon, 21 Dec 1998 09:17:34 -0800 (PST) (envelope-from pnadeau@wave.home.com) Received: from localhost (pnadeau@localhost) by foonly.scimitar.org (8.8.5/8.8.5) with SMTP id MAA14037; Mon, 21 Dec 1998 12:17:31 -0500 (EST) X-Authentication-Warning: foonly.scimitar.org: pnadeau owned process doing -bs Date: Mon, 21 Dec 1998 12:17:30 -0500 (EST) From: Patrick Nadeau X-Sender: pnadeau@foonly.scimitar.org To: wollman@FreeBSD.ORG, hackers@FreeBSD.ORG Subject: Locking arp entries Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Originally sent to: wollman@freebsd.org I recently had to make a mod to the kernel to fix a problem I had with arp. I'm letting you know in case anyone else is interested in it. In a nutshell I have an internal ethernet on the 10 network. I have a number of machines on the inside and a multihomed FreeBSD box connected to the Rogers @home service. It serves as a firewall and does the NAT for the machines on the inside. Somebody hooked up his machine to the Rogers network as 10.0.0.2. This caused gratuitous arp packets to reach my firewall and corrupt the arp entries for my inside host 10.0.0.2, making it unreachable. The problem persisted for a whole day and became so bad I decided to add a routing flag RTF_LOCK and some logic in in_arpinput to ignore packets if the flag is on. I also added code to set the lock flag to arp(8). I am mentioning this to you because I noticed the comment TODO: add "inuse/lock" bit in if_ether.c and assumed somebody meant to get around to do it. Let me know if you want to see the patches, it's not rocket science but it really fixed my problem! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message