I recently noticed I was unable to reach our “HP OfficeJet Pro 6960 All-in-One” printer over the wireless network.
For background, the wireless network is built on a couple of Unifi NanoHD access points which have worked flawlessly since the day they were installed.
The diagnostic printouts showed the printer was connected to Wifi and had a decent signal strength. The Unifi Controller software validated this by reporting the printer as also being connected but in spite of this, I wasn’t able to ping or otherwise communicate with the printer.
After following the usual tricks of restarting the printer, PC and access points, I changed the 2.4Ghz wireless channels from their previous auto values and hard coded them to channel 6 for the AP closest to the printer and channel 11 for the other AP.
The printer was immediately available and started spewing out the vast amounts of documents my wife had repeatedly sent in frustration.
To finish up, I then disabled the WIFI AI beta feature in the Unifi controller to prevent the controller moving the channels around again automagically.