2 adsl connections load balancing with natd/ipfw

[Rene de Vries]

Mitch,

Why so complicated.

Simply start two different natd instances one for each ADSL line. Make 
one of the ADSL lines the default route. Then based on the source 
address (just modified by natd) fast-route traffic which tries to leave 
via the default route over the wrong interface to the other interface's 
next hop (using ipfw).

You could apply various methods of determining over which ADSL line the 
traffic will leave, e.g. source port, source address, dest address 
etc...

This solution doesn't require provider assistance and would even work 
when you have two different providers.

René

On May 26, 2004, at 2:59, Mitch (bitblock) wrote:

> Hey David - didn't see your reply before I replied to Joe there - any 
> more
> info appreciated - I have both ends of the solution (I think) - just 
> need to
> know the best way to config!
>
> Consider these ip's and interfaces... what do I do? Is ISPF lighter 
> weight
> than BGP (considering the limited deployment?)
>
> Client A <-----\
>     X.X.X.2     \
>                  ----------> Router <------------->
>                  / / X.X.X.1         X.X.Y.2
>       X.X.X.3   / /
> Client B <-----/ /
>          <------/
>       X.X.X.4
>
> Router is FreeBSD based, and Client A and Client B are also FreeBSD 
> based,
> and have a second interface to the internal networks at Client A and 
> Client
> B.
>
> I'm wondering if my other problem (the fact that Client A can't see 
> Client B
> as there is an ATM path for it to Router, but as Client B's addresses 
> are on
> the same subnet, and not bounced off the Router (and there is no 
> direct ATM
> path) there is no connection...
>
> Any help or advice greatly appreciated.
>
> Thanks.
>
> m/
>
>> -----Original Message-----
>> From: owner-freebsd-isp at freebsd.org
>> [mailto:owner-freebsd-isp at freebsd.org]On Behalf Of David J. Hughes
>> Sent: Tuesday, May 25, 2004 4:08 PM
>> To: 'Joe Hamelin'; freebsd-isp at freebsd.org
>> Subject: RE: 2 adsl connections load balancing with natd/ipfw
>>
>>
>>
>> Actually, that isn't quite correct.  You do not need a virtual IP
>> address (such as an HSRP or VRRP setup).  You just need equal cost
>> paths from the ISP to you.
>>
>> To achieve this you will need to route an address range from your
>> ISP to your network.  It can be your address space, a small piece
>> of ISP provided space, or even a chunk of private space.  Just as
>> long as it's routed from the ISP to you via the DSL tails.  The
>> ISP just needs to see equal cost paths to your prefix via BOTH
>> your DSL tails.  That way they will use both.
>>
>> There are several ways to do this (inc running eBGP or OSPF to them
>> from your equipment).  Have a chat with your ISP to see what options
>> they would consider.
>>
>>
>> David
>
> _______________________________________________
> freebsd-isp at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-isp
> To unsubscribe, send any mail to "freebsd-isp-unsubscribe at freebsd.org"
>
-- 
René de Vries <rene at tunix.nl>
Tunix Internet Security & Training