Connecting an External DSL Modem to a Cisco Router

[taliesinu]

All,
I have a home network setup as follows:

A segment w/ 2 Windows machines, and 1 Sparc5 which is connected to a 100m switch. The switch is connected to a Cisco 2501 router, which is connected via serial1 to another Cisco 2501 router. The second router is connected via crossover cable to a Linux machine running as my internet gateway/firewall (dial-up)
Rather complex, I know, but sure makes a fun network lab!

And now the question:

I am upgrading to DSL in a few days, and the ISP is sending me a Westell 517 DSL Modem. The modem only supports 1 client machine. I would like to move the Linux machine to the subnet w/ all the other computers, and connect the DSL modem directly to the 2nd Cisco router. Then, run NAT from that router so that the DSL modem only sees one client machine. Lastly, I would like to have the Cisco router forward all port 80 and 21 traffic (from the outside) to my internal server. Any ideas on the feasibility of this, or configuration examples would be greatly appreciated.

Thanks in advance,

Thomas C. Gerlach
CCNA, Network+, A+

 

[jsauce]

It seems to be simple. DSL --> ROUTER --> LINUX/NAT/FIREWALL --> HUB/SWITCH < -- CLIENTS

Shouldn't be too difficult.
Just make sure you forward everything from the router directly to the linux machine, and masq it from there. You could technically forego the router altogether and route from the linux machine. Either way the linux machine will need two NICs. John D. Saucier
jsauce@magicguild.com

http://www.magicguild.com

Certified Technician