HP Jetdirect J7974E Administrator's Manual page 67

If you need to configure more TCP/IP parameters than allowed by control panel configuration, use an
alternate configuration tool (such as Telnet/IPv4 or the embedded Web server) as described in this
guide.
If the HP Jetdirect print server is configured with TCP/IP parameters from the printer control panel, the
configuration is saved on the print server when powered off/on.
ENWW Using the Printer Control Panel 57