I had an unwritten rule from a long time ago to never bother with third-party software firewalls and only stick with built-in Windows Firewall. In my experience, third-party firewalls (that come with endpoint security packages) never play nicely on business networks. Recently, I broke that rule while deploying Bitdefender endpoint security solution for a small business. I left the firewall enabled during testing and it didn't seem to cause any issues. I thought, well maybe it's time to throw away my unwritten rule and embrace Bitdefender firewall.
That came to bite me a few weeks later. One of the home users rang complaining that he could no longer print to his HP Envy 5000 printer. Scanning worked fine, but Windows was showing the printer as offline. Quick network check didn't indicate any issues. The printer was online, on its usual IP address, even HP printer utility was showing the printer as online with correct remaining ink status and settings accessible as usual.
I thought a quick re-install will certainly fix it... How wrong I was! Nothing I tried worked. Removing the printer wasn't a problem, but there was just no ways to install it back. HP installer would get stuck on "installing network device" stage for 10-15 minutes and then fail. Windows automatic printer installer was looking promising at the beginning but after the install, it would appear as a scanner with no printing ability with "driver is unavailable" message. Adding the printed manually via Control Panels > Devices and Printers > Add a Printer was going nowhere either. After entering the printer's IP, it would think for a little while and then complain that device on that IP was not recognised as a printer... No amount of uninstalling, reinstalling, rebooting, removing drivers via Print Server utility did any good. The laptop being slow as sloth didn't help either.
And then, after a good few hours of wasted time, I remembered about a recent Bitdefender Endpoint Security upgrade and my broken third-party firewall rule! Without expecting too much I created a test policy on Bitdefender GravityZone portal with firewall disabled and applied it to the laptop in question. Run the HP installer again, and... yes, it installed without any complaints and everything was back to normal.
So, yes, the third-party software firewall no-no rule is firmly back in place. Thanks, Bitdefender, but no thanks...
Windows 10 Pro
HP Envy 5000