How would I go about doing this?

How would I go about doing this?

[Zane C. B.]

I have two routers. The main router than everything goes through and a
second router that I want to route some traffic through depending on the
originating IP#.

The second router has filtering and the like running on it.

For traffic coming from a specific IP# and hitting the main router, I
want it then to be routed out through the second router.

Currently I got it working for port 80, using iptables, since squid is
setup transparently on the filtering router. The command I am using is
this... iptables -t nat -A PREROUTING -s <machine to filter for> -p tcp
--destination-port 80 -j DNAT --to-destination <filtering router>. This
works, but only for like web or the like which has a transparent squid
setup to take care of it.

That works for right now, but what I want to accomplish is to have the
main router kick packets, from specified IP#, out to the secondary
router.

Re: How would I go about doing this?

[John A. Sullivan III]

On Mon, 2005-10-17 at 13:37 -0500, Zane C. B. wrote:
> I have two routers. The main router than everything goes through and a
> second router that I want to route some traffic through depending on the
> originating IP#.
> 
> The second router has filtering and the like running on it.
> 
> For traffic coming from a specific IP# and hitting the main router, I
> want it then to be routed out through the second router.
> 
> Currently I got it working for port 80, using iptables, since squid is
> setup transparently on the filtering router. The command I am using is
> this... iptables -t nat -A PREROUTING -s <machine to filter for> -p tcp
> --destination-port 80 -j DNAT --to-destination <filtering router>. This
> works, but only for like web or the like which has a transparent squid
> setup to take care of it.
> 
> That works for right now, but what I want to accomplish is to have the
> main router kick packets, from specified IP#, out to the secondary
> router.
> 
If I understand you correctly, iproute2 is your friend.  You can
probably find the documentation on it in a file in your distribution
named ip-cref.ps.  You can also find a training slide show in the
training section of the ISCS open source network security management web
page (http://iscs.sourceforge.net).  Hope this helps - John
-- 
John A. Sullivan III
Open Source Development Corporation
+1 207-985-7880
jsullivan@opensourcedevel.com

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