HP is still offering free technical advice for the HP 3000 through its IT Response Center experts Web site. Just this week, an Hewlett-Packard support specialist who moderates the board answered a question about configuring a 3000 for a private network.
You can browse that HP Forum for answers to questions at the MPE/iX Web page. HP's advice might not be any better or worse than a third party support expert's, but at least the vendor is still answering questions from the 3000 community. For example, here's a recent Q&A between a user and an HP Canada networking expert.
HP moderator Emile Kwan Fong said
This is done using the NMMGR program. To configure the IP and Subnet mask, go to the path NETXPORT.NI.<NIname>.PROTOCOL.IP.
Kwan Fong, who's been answering questions for the past eight years on the site, added
To configure the gateway, go to the path NETXPORT.NI.<NIname>.INTERNET. You can leave the the default @ for the "reachable networks" fields. Make sure you validate NETXPORT.
You may want to stop/restart the network or hard boot (start norecovery) the 3000 for the changes to take effect.