Well, this didn't work. Thanks to Joe for trying to help, and a big thumbs-down to Xerox for selling us a product that a simple forgotten password becomes an insurmountable obstacle.
Check your messages, reset code has been sent.
Send me a PM with the Serial number and page count and I will try and get you a reset code.
We have at least one 6700DN that has a password set, and nobody has any idea what it is. Googling turns up hints for some other products, but nothing that helps me here. How do I reset the password, even if that requires resetting the entire printer to factory defaults?