Re: cisco 2501 problem

On Thu, 3 Jun 1999 12:22:28 -0500 Carlos Diaz <sysadmin@ahora.net> wrote:

> Hi list I'm new on linux so please don't kick me.
>
> I'm trying to set up my cisco router to do transparent proxy. I'm using the
> serial 0 to connect to my ISP and ethernet 0 for my lan. This is the
> configuration that i have in my rourter where *.*.*.* is the ip of my linux
> server.

Have you set the Linux box to accept packets addresses to other IPs?
(You probably need to do address translation to rewrite anything
received through the Ethernet, sent to TCP/80 on a different IP from the
server itself to the IP of the server TCP/8080).

The Cisco stuff only sets the 'next hop' field of the packet, so that the
packet is delivered to the Linux box. It does not change the destination
IP address of the packet. The TCP/IP stack in the Linux box will not
pass packets up to applications when the IP address is not one of those
defined for the box.

I'm afraid I've not played with the new IPFWADM stuff under Linux 2.2, so
you'll probably need to look at 'ipchains' or something to do this. On a
Solaris box, we used a kernel level network address translator module to
do this (although we don't do this anymore; we only used this to put up a
'sorry - you'll have to use the cache' page for a few weeks).

  - Bob

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Received on Thu Jun 03 1999 - 12:13:53 MDT