I would like to set up a lab in my basement using my Cable Modem internet connection. I have two cisco routers that I would like to connect behind my cable modem to setup two Internal Networks. Is there a way to connect the two routers to one another in order to simulate a WAN? And is it possible to connect a cable modem from the ISP to a serial port on one of the routers?

Yes, you can cross connect the two routers. No, you can't connect the cable modem to the serial port. The "Console" port (serial) is solely for connecting directly from a PC (or laptop) and intended for setting up the router(s). What model routers? From your questions I get the impression you don't know much about Cisco equipment and the IOS inside them....I hope you have a good book and a good working knowledge of routing and routing tables. If you don't, you're going to have a lot of trouble. In your case, I would work on getting one router to work first. Then connect the second one.

Oh, I was going to mention, you only need one router to create two, or more internal networks depending on what you have for a switch (or switches as the case may be). If you have a managed switch (or switches) that are capable of passing VLAN tags one router will suffice for internal networks. Multiple routers would be used more for a WAN to connect multiple remote sites.

Yeah you can connect the routers together via serial ports and simulate a WAN link without ntu's (csu/dsu). You can encapsulate frame-relay, ect...

IMradams921 can probably also benifit from this.I have two cisco 2501s connected back to back via their serial port. However, cannot ping the ethernet ports of the other router. Router1 cannot ping router2s ethernet port & viceversa. (using console port, and all ports & protocols up). Any idea what is the problem. Here is my data: ------------------- Router1#sh run Building configuration... Current configuration: ! version 11.3 service timestamps debug uptime service timestamps log uptime no service password-encryption ! ! interface Ethernet0 ip address 192.168.2.1 255.255.255.0 no cdp enable no mop enabled ! interface Serial0 ip address 192.168.3.1 255.255.255.0 no ip mroute-cache no fair-queue ! interface Serial1 ip address 192.168.3.3 255.255.255.0 no cdp enable ! router rip network 192.168.0.0 ! ip classless ! snmp-server community public RO ! line con 0 exec-timeout 0 0 line aux 0 line vty 0 4 password 300 login ! end Router2#sh run Building configuration... Current configuration: ! version 11.3 service timestamps debug uptime service timestamps log uptime no service password-encryption ! ! ! ! interface Ethernet0 ip address 192.168.7.1 255.255.255.0 no cdp enable no mop enabled ! interface Serial0 ip address 192.168.3.2 255.255.255.0 no ip mroute-cache no fair-queue clockrate 56000 ! interface Serial1 ip address 192.168.6.1 255.255.255.0 clockrate 56000 no cdp enable ! router rip network 192.168.0.0 ! ip classless ! snmp-server community public RO ! line con 0 exec-timeout 0 0 line aux 0 line vty 0 4 password 300 login ! end Router2# -