2 adsl connections load balancing with natd/ipfw

[Mitch (bitblock)]

Hi Rene!

That concept was recently suggested to me by a friend on another project - I
haven't had a chance to try it yet though - any pointers on a starter rule
set greatly appreciated...

thanks.

m/

> -----Original Message-----
> From: Rene de Vries [mailto:rene at canyon.xs4all.nl]
> Sent: Sunday, June 06, 2004 10:47 AM
> To: Mitch (bitblock)
> Cc: 'Joe Hamelin'; freebsd-isp at freebsd.org; David J. Hughes
> Subject: Re: 2 adsl connections load balancing with natd/ipfw
>
>
> 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
> >
> > _______________________________________________
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> > http://lists.freebsd.org/mailman/listinfo/freebsd-isp
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> >
> --
> René de Vries <rene at tunix.nl>
> Tunix Internet Security & Training
>
>