Printer will not print when connected to network

[alkat53]

Printer will not print when connected to the network.  When it is connected via usb it prints fine, you can run reports etc.  When it is connected to the network it says it's printing but never does, any report you try and run it comes up with a 49 service error code.  

I spent all Friday on chat with HP and they determined it was the network (we did have a new modem installed and the printer worked fine before that.)  I called Brighthouse, our network provider, today and they say there is nothing wrong on their end.  

Does anyone have any clue?  I have unplugged, reset, redownloaded software, changed ethernet cords.  I am now at the point of pulling my hair out...

Thank you in advance for any help you can give me.

[Stratospaly]

I have the same situation but have a bit more to add.  Used 3 M402N printers, 2 different firmware versions, 5 different network drops on 2 different switch stacks, DHCP and static IP, printing through an IP phone and dumb microswitch, and none of this allows me to print with a live network cable attached to the printer.  I cannot even print a Config report from the buttons of the printer with the network cable attached.  Unplug the cable and I can print USB and through the front panel.  

I also plugged into the dumb switch without that switch being on the network and could print, so its not just the act of a hot network cord being plugged in, its something about the type of network traffic that is causing 49 service error.  This is also ONLY happening on the M402N printers.  

I would love some clue to a resolution on this or we will have to return the M402N printers for another model.  

[Stratospaly]

Figured it out.  Disable ipv6 on the printer and it now prints fine on the network.