Difficulty Routing Cable to Multiple PC's 3

[srossbach]

I have recently converted from a DSL service to Cable service and cannot get my second computer online.

I am using Comcast Cable High Speed Internet with Motorola SB4200 SURFboard Cable Modem. I am attempting to connect my PC's using my Linksys Ethernet Cable / DSL Router - Model BEFSR41. The router show active lights for the Modem and both PC's - BUT only one PC will actually connect to the internet. The other seems to detect IP address from some other source.

Any ideas?

Remember to smile - it makes everyone wonder what you are up to!

 

[TheOldMan346]

srossbach,

You're probably switching from a DHCP or PPPoE setup on DSL to cable. Cable systems often use the MAC address of the network interface to register the service. The IP addressing may be either static or DHCP.

In english, you're probably getting a single IP address from the cable provider. The cable system is grabbing the identification from the first computer and saying anything else on the circuit is bogus so they are not providing service to it. This includes the router an dthe other computer.

Find the MAC address of the computer that is able to surf the internet by opening a command prompt/DOS window and typing "IPCONFIG /ALL" without the quotes. You wil see a set of six two diigt numbers on the network interface called "Physical address". Write them down. Open the router's web interface by browsing to

http://192.168.1.1.

Then click on the Advanced tab and click again on the "MAC Address Clone" tab. Enter the set of numbers of the network adapter's physical address written down earlier here. Apply the changes.

To get it to register, you may need to shut down the cable modem and router then restart the modem and then the router.

Don't know who your provider is but it may also be necessary to call them and register the MAC address but try the above first.

Hope that helps.
The Old Man

 

[ciscogeek36]

Make sure your router has dhcp enabled. Make sure there are at least as many addresses in the dhcp table as computers you have and give them an address i.e. 192.168.1.100/101...and save the changes..

if you have a static ip, then put that in the routers WAN ip. if you have a dynamic address then 'detect address automatically' will do.

of course checking the cabling is always a good idea. saved me a few times..any other questions, feel free to ask.

 

[pfleischman]

The MAC address clone feature should work. Also note that some of the Motorola cable modems have an online/offline button. When in the offline mode, the modem functions as a DHCP server (using the 192.168.x.x range), allocating 192.168.x.1 to itself and serving address (though no net access) to any computers connected to it. As soon as you put it into online mode, it reverts to normal function, dumping the local address (and DHCP server) in favor of the one received from the ISP and authorizing with a combo of the MAC addresses of the modem and the computer's NIC (see above).

I have also seen some of the Motorolas that actually function as routers themselves and all you need is a hub/switch instead of a seperate router. As far as I've seen, the one's that need the MAC address workaround all have the online/offline button.