Unable to verify the printer on the network

Question

Hi,
I have a home IP network with an HP4100N network laser-printer connected via JetDirect card to a powerline device and then to a hub.
Up until recently, all computers on my network could successfully print to the printer via the JetDirect card and IP (192.168.0.100).
HOWEVER, my girlfriends MacBook Pro running Mac OX 10.9.5 suddenly stopped printing to the printer and things were just starting to build up in the print queue. The printer continues to print normally for everyone else on Mac and even a Windows 7 machine, eeek!
Turning the printer on and off a couple of times, resetting the network etc, I then finally deleted the print queue and tried to setup a new connection to the printer again on her computer via the prefs and the IP JetDirect socket option (like I have done on all the other computers).
When I enter the printer IP address into the Mac Printer & Scanners settings, Mac OS tried to interrogate printer model etc and it comes back with a Generic Postscript Printer profile and not the HP specific one. (Again, every other computer can setup fine at this point!)
On her computer, when you try and install the printer with the wrong profile (or even the correct one if manually chosen), it eventually says:
'Unable to verify the printer on your network'.
Network utility:
I then tried using the Network Utility to ping the printer from my laptop, this works.
I tried to ping the printer from her computer, this doesn't work and it times out!
then...
I tried pinging her MBP from my MBP and this works. Then I pinged my MBP from her MBP, this works.
So her computer is on the network, but is not able to see the printer.
I then hard- IP'd a new IP address on the printer (just to rule this out), setup all the computers to this new printer, all worked well except for her computer, which once again couldn't see the printer. (I can't ping to it either again from her computer, even with the new IP!)
I think I've tried all the obvious things, updating software, resetting things, turning the firewall off completely....but all to no avail.
The problem, it seems to me, is with her MBP rather than with the network or the printer (as all other computers can print!).
So...the million dollar question is... Can anyone tell me what is going on?! How do I get her computer to print to this printer again??
thanks very much.

Answer 1

Yeah, I would agree with you completely Greg, but the baffling thing is it just affects this one Mac. How come it routes 'selectively' so to speak? It works for everyone (incl. Windows 7 machine) but not for my GF's MBP... until such a time that it suddenly feels like working again (all by itself by the looks of things).
You are right in saying that it defo appears to be some kind of routing problem, but I'm having difficulty in finding out where the problem actually is. Is it the router, the printer or her computer? Could it be the firewall on the router blocking it for her and not for others for some reason? If it was the router, you would expect it to tarnish everyone with the same brush, would you not?
Whilst the HP printer has the static IP manually set up on that side (192.168.0.100), the router hasn't specifically been told that the printer has the .0.100 address hard coded into it I don't think, so there is a possibility for it to be going weird here. I'll need to look at the router config page tonight and just lock that 0.100 address to the MAC HW of the printer. Perhaps that will do the trick, but still wouldn't explain why it's doing it selectively just to that one computer (not even randomly to others on the network).
I did try the safe boot too. Within that I ran Disk Utility to fix some file permission errors (there were some group permission problems for the new HP software that I had installed on her computer actually, which DU had fixed). Whilst running the utility, it did throw back issues about the EFI partition map being corrupted etc, but that seems to be a separate problem with the disk utility software not being able to run/fix from the disk it is being booted from, even in safe mode. But this is being discussed elsewhere on Apple Forums and I don't think it's connected to the IP problem I'm having.
Whilst I was doing the Safe Boot thing, I got sidetracked (isn't that always the case when you troubleshoot) and didn't try and set the printer up within that environment, but instead was trying to figure out why I was getting the EFI partition Map errors. It turned into a late night and I had to hit the sack at some point...
I tried IPP too. Putting the Printers IP into the address field on her computer didn't result in the HP Printer profile being selected when it tried to find the printer, this stayed as Generic PostScript. I didn't explore any further on that occasion to see if I could manually set it all up and print to it or if the set-up would just hang again. I figured if the IP address of the printer isn't visible to the computer (ie. no route to host), then changing to IPP wouldn't work either.
I'll give these options another go tonight when I get my hands on her computer again.