From owner-freebsd-questions@FreeBSD.ORG Thu Jun 23 23:55:52 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 139B816A41C for ; Thu, 23 Jun 2005 23:55:52 +0000 (GMT) (envelope-from lists@immuneit.com) Received: from web1.nidhog.com (web1.nidhog.com [66.207.132.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id C608E43D49 for ; Thu, 23 Jun 2005 23:55:51 +0000 (GMT) (envelope-from lists@immuneit.com) Received: from blacksea.nedyah.org (semcheski.squirrelhill.nidhog.net [66.207.143.104]) (authenticated bits=0) by web1.nidhog.com (8.13.1/8.13.1) with ESMTP id j5NNtpiY062113 for ; Thu, 23 Jun 2005 19:55:54 -0400 (EDT) (envelope-from lists@immuneit.com) From: "Michael H. Semcheski" To: freebsd-questions@freebsd.org Date: Thu, 23 Jun 2005 19:46:46 -0400 User-Agent: KMail/1.8 References: <5591e955475b.55475b5591e9@liu.se> In-Reply-To: <5591e955475b.55475b5591e9@liu.se> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200506231946.47626.lists@immuneit.com> X-Greylist: Recipient e-mail whitelisted, not delayed by milter-greylist-1.5.6 (web1.nidhog.com [66.207.132.2]); Thu, 23 Jun 2005 19:55:54 -0400 (EDT) Subject: Re: NAT router confusion 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: Thu, 23 Jun 2005 23:55:52 -0000 On Thursday 23 June 2005 07:43 pm, Ulf Magnusson wrote: > Is this router really some switch/router hybrid? Or..? Bleh, someone > please sort this out for me. I realize this isn't strictly > FreeBSD-related, but I simply couldn't think of a better place to pick > brains, so I hope I'll be excused :) It is a switch / router hybrid. If the traffic is going to an address on the same network, its a switch. If the traffic is going to an address on a different network, its a router. If you understand that concept, then you should have a pretty good idea of how the system works. I do not have a complete enough understanding of IP networks to explain this in specific detail. I think the key is that the computer generating the traffic looks at the netmask for the sending interface (eg, 255.255.255.0) and uses this to determine if the endpoint of the traffic is on the same network or not. If it is, it sends the traffic directly to the host. If it is on a different network, it forwards the traffic to the gateway address. Mike