Epson AcuLaser C8600 Administrator's Manual page 242

Note:
To activate Network Menu settings, you must turn off the printer
for more than five seconds then turn it back on. Or, you can perform
a Reset All operation, as explained in "Reset Menu" in the Reference
Guide.
Resetting the printer erases all print jobs. Make sure the Ready light
is not flashing when you reset the printer.
232 Setting an IP Address for the Printer