In part 1 of my printer odyssey — Fixing an HP printer that had “Encryption credentials expired” — I got my one of my client’s two printers printing from his Mac again via an arcane technical fix.
But that was nothing. Bill’s wife — let’s call her Diane — also had a printer, and it was the primary printer both of them used for printing. Bill couldn’t print to that one anymore, either.
This printer, I noticed, did not show up on the network when clicking “Add Printer.” So, I figured there was likely some kind of network problem. After some fairly standard network troubleshooting that revealed nothing unusual, I took a deeper look at the printer.
Its model was an HP 4000N. And that printer…wait for it…was produced from 1997 to 1999. So it was about 24 years old. And until recently, they’d still been able to print to it! HP, in the day, really made their printers to last forever.
This printer was so old it didn’t even have a USB port. It had, as was normal at the time, a serial port, and a parallel port, both of which are now obsolete; and it had three network ports, one for Ethernet (which was how it was connected, and how was able to still be used at all), and two other kinds for no-longer used network types — LocalTalk, which old Mac computers used to use, and Thinnet, which only network admins from the 90’s are likely to remember. My college used it in one of its labs.
I walked Bill through the instructions to print out a network status sheet, by pressing whatever invocation was required from the printer’s control panel, and he sent me a picture of the result. It gave me lots of clues.
First off: Date manufactured. 09/1998. Holy crap. Still running!
Next: Config by: User Specified, IP Address: 192.168.1.201.
What this told me is that…years ago, who knows when, I hardcoded an IP address into the printer through its control panel. I knew it had to be me, even though I’d forgotten, because I always give a printer .201, .202, or .203 when I do that.
This kind of manual address specification, called a static IP, is a pretty unorthodox thing to do. Normally, your router manages the IP addresses of devices on your network. In the unusual case where you need your printer to maintain a consistent address on your network, you create what’s called a reservation in your router, where it knows to always assign an address to the unique network ID in the hardware of your printer.
In trying to think about why I might have done it this way, I surmised it could have been either of the following: at some point in the distant past, Bill and Diane had an underfeatured router that couldn’t do a DHCP reservation; or the printer was so old it didn’t support DHCP, or to that the extent that it did supported, it didn’t work reliably.
At any rate, the printer had a static IP address, and I wasn’t about to ask Bill over the phone to start fiddling with the tiny buttons and screen on the printer to see if there was a better way. And, it had worked recently, so it should be able to work again.
When you add a printer on a Mac, you normally are shown a network browser which reveals all the printers detected on your network. But one of the tabs at the top reveals another option: adding a printer by directly specifying its IP address. Now that I knew the IP address, I tried to do that, but I just got an error that the printer couldn’t be communicated with. So I tried entering the IP address into a web browser, and was told that the connection was refused.
Going back to my sheet of paper, I found another clue: “ARP Duplicate IP Address.” That suggested that some other device on the network was given the same IP address as the one the printer was demanding for itself. When you have the same IP addresses on the same network, one or both of those devices can’t be communicated with. It’s a conflict. Which is why you normally leave your router to sort out your network’s IP addresses.
The router was one provided by Verizon, so I logged into its configuration screen for administrators, but was unable to find which device that might have been. But it was still the very most likely explanation for the problem, especially given what was shown on the printer configuration page. So I set the router to assign address only up to .199, so that no other device would end up with the .201 used by the printer. I restarted the router, meaning all devices on the network would get newly assigned addresses once it was back up and running.
And voila. I was able to add the printer by its IP address, no muss, no fuss, and Bill was back in business. Whatever other device was causing issues was assigned a new, non-conflicting address, and likely working fine.
As for why it was working before, and not now? Hard to know, but I’m guessing it was just lucky that the problem hadn’t emerged until then. A new device may have been added to the network that wasn’t there before, and it finally got the same IP address as the printer. Or there had been a series of power outages, and maybe during one of the router restarts, it assigned the printer’s address to a device which previously had a different address.
Diane, though, wasn’t quite done. I’ll cover how I got her printing again in part 3 of 1998: A Printer Odyssey.
Image: From the movie Office Space