You’ve checked all the basics — the cables are connected, the printer is powered on, and both devices have been restarted. But your printer still shows “Offline”? One often-overlooked reason is your computer’s security software, like a firewall or antivirus, which may be unintentionally blocking the connection.
This guide from printconnectguide.info explains how your security settings might interrupt printer communication and offers simple, step-by-step actions to help restore proper printing without uninstalling software or drivers.
⚠️ Disclaimer
This article is for informational purposes only. We are not affiliated with or endorsed by any printer or software company. No downloads, support services, or remote access are provided. For product-specific information, please refer to your printer brand’s official website.
🔍 Why Security Software Might Interfere with Your Printer
Firewalls and antivirus programs are designed to protect your computer by monitoring incoming and outgoing network traffic. In some cases, they can mistakenly identify your printer’s communication as a threat — especially if it’s a network printer (Wi-Fi or Ethernet connected).
Common Signs:
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The printer worked before but suddenly shows as offline after a system or security software update
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You can open the printer’s IP address in a browser, but you can’t print
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Printing works briefly after disabling the firewall or antivirus
🧪 Step 1: Temporarily Disable Security Software (For Testing Only)
✅ This is just to test if the firewall is causing the issue. Re-enable protection immediately afterward.
A. Windows Defender Firewall
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Go to Start > Settings > Privacy & Security (or Update & Security)
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Click Windows Security > Firewall & Network Protection
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Choose your current network (Private or Public)
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Turn Microsoft Defender Firewall to Off
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Try printing a document
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Turn the firewall back on immediately
B. Third-Party Antivirus or Firewalls
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Right-click the antivirus icon from your system tray
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Select an option to pause or disable protection (e.g., “Pause Protection”)
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Attempt to print
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Re-enable the protection afterward
🔧 Step 2: Add a Firewall Exception in Windows
If the printer works after disabling the firewall, allow it permanently:
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Go to Start > Settings > Windows Security > Firewall & Network Protection
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Click Allow an app through firewall
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Click Change settings
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Locate your printer software in the list
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Enable both Private and Public network checkboxes
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If missing, click Allow another app > Browse, then select your printer’s main application
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Save and restart your computer
🔐 Step 3: Configure Exceptions in Third-Party Security Software
If using antivirus/firewall software from another provider:
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Open your security app and find “Firewall,” “Network Protection,” or “Exceptions”
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Add your printer’s IP address to the allow list
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Allow access to printer-related applications (like the print monitor or spooler)
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If available, manually allow common printer ports:
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TCP 9100 (Raw printing)
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TCP 631 (IPP)
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TCP 515 (LPD)
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UDP 161/162 (SNMP)
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Refer to your printer’s manual or official website for precise port details.
🏠 Step 4: Set Network Profile to “Private”
Ensure your computer recognizes your current network as Private (home/office), not Public, for smoother device communication.
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Go to Start > Settings > Network & Internet
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Click Wi-Fi or Ethernet
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Select your current network
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Set the Network profile to Private
✅ Final Thoughts
Security software helps keep your system safe — but it can occasionally block printers from working correctly. By performing a quick test and adjusting firewall permissions, you can often resolve the “Offline” message and restore printing without reinstalling anything.