Configure USB Modem

[soumyabratapaul]

I have a modem which was supplied by my ISP which came with 4 ethernet ports and 1 USB. Unfortunately they gave me 1 ethernet cable and 1 USB cable. Now the problem is I have 3 PCs. Now one of the PC I need constant internet where my family works, so it is connected via the ethernet cable. now the other 2 PC have ethernet ports but I do not have spare ethernet cables. Now I am left with 1 USB cable only to connect to the internet So how do I configure, the USB cable, because Ubuntu 11.04 is not recognizing it is a modem, and as a result the network connections tab is not highlighted in GNOME panel. Please help.

[gandaran]

I once had a modem that could either connect with usb or ethernet but could not use the two at the same time, this was the modem problem not ubuntu, try the ubuntu PC with USB cable, remove the ethernet cable from the modem just to see it USB works, if it does then maybe the solution is to manually set a static IP for each USB and ethernet connections.
or buy spare ethernet cables, they aren't expensive.