(This will make no sense to anyone that doesn’t know what this is, but I’m contributing to Google by duplicating the info here.)

I was helping a friend get their new cable modem up and going, and we couldn’t find the WEP key anywhere. It turns out that for this model, the information is as follows:

Factory default WEP keys are 128-bit, and the key is the cable modem MAC address plus 14

zeros. Example: 00028A861 11800000000000000

So there you go, future newbies to this cable modem. ;-)