From owner-freebsd-isp Mon Sep 16 6:35: 8 2002 Delivered-To: freebsd-isp@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0EBFF37B400 for ; Mon, 16 Sep 2002 06:35:07 -0700 (PDT) Received: from tomts17-srv.bellnexxia.net (tomts17.bellnexxia.net [209.226.175.71]) by mx1.FreeBSD.org (Postfix) with ESMTP id 13D9443E72 for ; Mon, 16 Sep 2002 06:35:06 -0700 (PDT) (envelope-from derek@durham.net) Received: from cerberus.motorcity.on.ca ([65.95.185.80]) by tomts17-srv.bellnexxia.net (InterMail vM.5.01.04.19 201-253-122-122-119-20020516) with ESMTP id <20020916133505.UOEJ3718.tomts17-srv.bellnexxia.net@cerberus.motorcity.on.ca>; Mon, 16 Sep 2002 09:35:05 -0400 Received: (from root@localhost) by cerberus.motorcity.on.ca (8.11.6/8.11.6) id g8GCjpP60247; Mon, 16 Sep 2002 08:45:52 -0400 (EDT) (envelope-from derek@durham.net) Received: from DEVELOPMENT ([192.168.254.4]) by cerberus.motorcity.on.ca (8.11.6/8.11.6av) with SMTP id g8GCjkD60239; Mon, 16 Sep 2002 08:45:47 -0400 (EDT) (envelope-from derek@durham.net) Message-ID: <003a01c25d86$267c8210$04fea8c0@motorcity.on.ca> From: "Derek" To: , References: Subject: Re: nat & load balancing Date: Mon, 16 Sep 2002 09:37:06 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Virus-Scanned: by AMaViS perl-11 ares.durham.net Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org > there are a lot of nat samples which show how to reverse proxy over > a farm of web servers but i have some difficulties in getting a sample to > work which nat outgoing traffic to the 2 isp's ip assignments, balancing > them. You definately would. If this is what you intend to do, I would suggest something like BGP, and dynamic routing, vs. what we've described. It is designed to do just what you are describing. Here's why NAT won't work: ---DSL FROM ISP1> 206.186.2.1 - BSD NAT - Webfarm 10/8 ---DSL FROM ISP2> 142.55.33.5 / Now suppose your DNS is www.mywebfarm.com -> 142.55.33.5 Any request to www.mywebfarm.com will _always_ go through ISP2, because they have the route to 142.55.33.5. When it fails, DNS is too slow to automatically switch to 206.186.2.1. In a BGP setup you would have: Now suppose your DNS is www.mywebfarm.com -> (Purchased Subnet) ---DSL FROM ISP1> 206.186.2.1 - router (Purchased Subnet) - Webfarm (Purchased Subnet) ---DSL FROM ISP2> 142.55.33.5 / when ISP1 fails, the router will modify the BGP routing table to announce all traffic to the Purchased subnet to travel through ISP2. In my initial post: > It could be done easily... you are not doing port > forwarding (ie, hosting a web server)... Derek To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message