From owner-freebsd-net  Thu Oct 26 19:31: 3 2000
Delivered-To: freebsd-net@freebsd.org
Received: from rapidnet.com (rapidnet.com [205.164.216.1])
	by hub.freebsd.org (Postfix) with ESMTP id DB72737B479
	for <freebsd-net@FreeBSD.ORG>; Thu, 26 Oct 2000 19:30:59 -0700 (PDT)
Received: from localhost (nick@localhost)
	by rapidnet.com (8.9.3/8.9.3) with ESMTP id UAA49488;
	Thu, 26 Oct 2000 20:30:57 -0600 (MDT)
Date: Thu, 26 Oct 2000 20:30:57 -0600 (MDT)
From: Nick Rogness <nick@rapidnet.com>
To: John Telford <j.telford@sympatico.ca>
Cc: freebsd-net@FreeBSD.ORG
Subject: Re: Multihomed natd, nics and default gateways continued.
In-Reply-To: <002601c03fa5$a760da30$0100000a@johnny5>
Message-ID: <Pine.BSF.4.21.0010262011060.29371-100000@rapidnet.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: owner-freebsd-net@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.org

On Thu, 26 Oct 2000, John Telford wrote:

> Nick,
> You are wise in the ways of FreeBSD and routing. Could you take a moment and provide some tips on how I could expand on your help to John Prince ?
> I have a similar setup but would like it to behave slightly differently. My setup:
> 1 internal interface.
> 1 external interface doing natd, default gateway routing for the internal to an isp.
> We have now brought in a second ISP and put a 3rd interface into the Freebsd box. I'd like to have a setup like this:
> 
> ISPA-----------interface A_fxp0
>                                 fxp2_NATD--interface C---------internal network 10.130.x.x
> ISPB-----------interface b_fxp1  
> 

> I would like to have all internal -> external traffic route through
> ISPA. In the event that ISPA goes down then the ISPB connection should
> take over automatically with out the users noticing except that things
> are slower because ISPB is a slower connection. This means the default
> gateway would have to change on the fly and I can't seem to locate
> much information on how this can work.


   For ipfw:

 	#Divert traffic from internal out and in interface ISP A
 	ipfw add 101 divert natd ip from any to any via $fxp0
 
 	#Divert traffic from internal network in and out ISP B
 	ipfw add 201 divert natd2 ip from any to any via $INTERFACE_A
 
 	#Leave on for testing until it works
 	ipfw add 3000 allow ip from any to any
 
   For natd:
 	Then after you do that setup the 2 different natd`s to listen on
 	different ports (default 8668) and another entry int
 	/etc/services:
 
		natd2           8669/divert # Network Address Translation
 
	Then run the nat`s seperately:
 
 		root# natd -p 8668 -n fxp0
 		root# natd -p 8669 -n fxp1

   For routing:

    Add 2 default routes, one primary (ISP A) and one backup (ISP
    B).  Since ISP A is a prefered route...it gets the more specific
    route:

      root# route add -net 0.0.0.0 $GATEWAY_IP_ISP_A -netmask 128.0.0.0
      root# route add -net 128.0.0.0 $GATEWAY_IP_ISP_A -netmask 128.0.0.0

      root# route add -net 0.0.0.0 $GATEWAY_IP_ISP_B -netmask 0.0.0.0


Nick Rogness
- Drive defensively.  Buy a tank.




To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-net" in the body of the message