Hi bill1wts, I'm in the same position. I'm trying to link two 998s (bow and console) and have the same problem...no network option.
I've already contact Humminbird Support and their advice was to update both units to the latest software and restore to default settings. This has been done with my 998s (update-to-date with the latest software version (6.490)) and I've restored defaults before connecting units. After performing these changes, I still do not have a network tab.
I've also notice there is no IP address in the self test view. Both units are brand new and the network cable is brand new as well.
bill1wts, you can view the software version in the self test view. When powering up, hit the 'menu' button when it mentions it and scroll down to System Status. This will give you the self test view and you can scroll across pages by hit the view button.
If anyone can provide advice on how to fix this problem for myself and bill1wts, that would be great.
Cheers,
Tim