I have a Ricoh (or Aficio or Nashuatec) printer-copier at office, a real workhorse but with a serious problem: its network printer functions get messed up when Universal Plug and Play (UPnP) is enabled on the LAN.
I've searched the web and I found out that this is a real problem with various Ricoh copiers. So I had to disable UPnP and manually forward ports for the various users and applications on the LAN which was a real headache.
Today I found that I can keep UPnP enabled as long as I block traffic on ports UDP 1900 and TCP 5000 on the printer's IP.
For example, my Aficio has a static IP 192.168.1.2
Going to Advanced > IP Filters, I created a rule called UPNPBLOCK with the following mappings:
Protocol, Port Start, Port End, Port Map
UDP, 1900, 1900, 1900
TCP, 5000, 5000, 5000
and I assigned this to 192.168.1.2
(Level of detail is high to help other web searchers apply the solution)
The printer now works without problems, at least on first tests. I'll add a reminder to post again if any problems arise.
Routertech 2.6 firmware but most routers have IP filtering.