Cisco Router w/ ADSL Modem

[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, and requires that the client use DHCP. 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 DHCP client and 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. I do know that I need IOS 12.1 for running the ethernet interface as DHCP client. Any ideas on the feasibility of this, or configuration examples would be greatly appreciated.

Thanks in advance,

Thomas C. Gerlach
CCNA, Network+, A+

 

[UNIX72]

Won't work with 2501 router. Are you using PPPOE for your DSL connection? You need IOS software with PPPOE client. If you use a ethernet interface for your DSL modem the router turns into a bridge which won't work in your situation. You need a router 800/1700/ DSL router with the ADSL wic card. I have a 2621 router with the ADSL card works just fine.