HP Color LaserJet: Unable to connect to the network

Posted by ads on Tuesday, 2020-06-02
Posted in [Hardware]

We have a HP Color LaserJet in the office, one of these devices which can do both printing and scanning. The newer versions include a very nice feature “Scan to network folder” - so I did setup options to scan different PDF sizes to all of our laptops. Very convenient!

Until it stopped working a while ago.

The printer refuses scans to a network folder with the error message: “Scan Error” “Unable to connect to the network. Check the network, and then try again.

Printer Error Message
Printer Error Message

Looking at the printer, it auto-installed a new firmware in April (CLRWTRXXXN002.2014A.00 - Built date: 2020-04-02). Dunno if that is related, but around the same time the scan function stopped working. Haven’t really found time to investigate, until now. For the couple cases I had to scan something, I used an USB stick.

First things first, I turned up the logging in Samba - all laptops here run Linux, and no Windows. This - and a tcpdump - did not reveal any new details, but showed that the printer does connect to the laptop, is authenticated as guest user, and then … does nothing. The error message Unable to connect to the network is a lie. Shame on you, HP!

Then I tried to limit the SMP protocol versions on the laptop:

client min protocol = SMB2
client max protocol = SMB3

Didn’t change a thing.

Last but not least, I changed the protocol versions on the printer:

  • Network
  • Advanced Settings
  • SMB
  • Disable SMB v3

After clicking Apply, the scanner was suddenly able to scan again to network folders!

It’s hard to implement protocols properly …

Categories: [Hardware]