From owner-freebsd-questions@FreeBSD.ORG Tue Aug 14 00:19:37 2007 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1DB7A16A419 for ; Tue, 14 Aug 2007 00:19:37 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from mail-out3.apple.com (mail-out3.apple.com [17.254.13.22]) by mx1.freebsd.org (Postfix) with ESMTP id 01ED913C468 for ; Tue, 14 Aug 2007 00:19:36 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from relay7.apple.com (relay7.apple.com [17.128.113.37]) by mail-out3.apple.com (Postfix) with ESMTP id 8C026E6ADA8; Mon, 13 Aug 2007 17:19:36 -0700 (PDT) Received: from relay7.apple.com (unknown [127.0.0.1]) by relay7.apple.com (Symantec Mail Security) with ESMTP id 754DF30076; Mon, 13 Aug 2007 17:19:36 -0700 (PDT) X-AuditID: 11807125-a2a1fbb0000007e5-72-46c0f5183ad0 Received: from [17.214.13.96] (cswiger1.apple.com [17.214.13.96]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by relay7.apple.com (Apple SCV relay) with ESMTP id 62A463006A; Mon, 13 Aug 2007 17:19:36 -0700 (PDT) In-Reply-To: <64c038660708131659m68620db9of8d93bd079d1fb29@mail.gmail.com> References: <64c038660708131659m68620db9of8d93bd079d1fb29@mail.gmail.com> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <5F59BCBE-FCEA-4D2A-8A69-E0CE9B3A86A0@mac.com> Content-Transfer-Encoding: 7bit From: Chuck Swiger Date: Mon, 13 Aug 2007 17:19:35 -0700 To: Modulok X-Mailer: Apple Mail (2.752.2) X-Brightmail-Tracker: AAAAAA== Cc: freebsd-questions@freebsd.org Subject: Re: Redundant network router setup? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Aug 2007 00:19:37 -0000 On Aug 13, 2007, at 4:59 PM, Modulok wrote: > QUESTION: Is there a way to setup a redundant router, such that I can > offload traffic from the primary router to another machine, without > breaking TCP sessions? There are several ways of setting up such redundancy; the common case which Cisco calls VRRP, you can use under FreeBSD as CARP. However, this approach is limited to pure routing; it does not handle replicating the NAT state tables: > BACKGROUND: I have a FreeBSD machine acting as a gateway, running > natd(8) through ipfw(8). ...which you mention you are using. I don't know of any way to provide redundancy for existing connections going via natd. -- -Chuck