Strange Terminal Prefix in bash

After using terminal for the installation of MySQL and a local Joomla development environment (hopefully unrelated) I am now getting a very odd prefix to my terminal prompt. Instead of getting

machine_name:~ user_id$

I'm getting

unknown406c8f4592cf:~ user_id$

Any ideas of what is going on here?

hostname returns 'unknown406c8f4592cf', the funny string in terminal. Hmmm.

Not sure why DHCP would use that name as there is a perfectly good name in Preferences/Sharing. Also, there doesn't appear to be any Terminal preference that would affect this.

Guess I'm confused.