How to Fix Lexmark Printer Offline Due to Firewall or Antivirus

I’ve been fixing printer issues for over a decade, mostly across small offices and home setups in the US and Canada. And I’ll be honest… when a Lexmark printer shows offline, nine times out of ten it’s not the printer. It’s something blocking it.

Most commonly?
👉 Firewall rules
👉 Antivirus interference
👉 Or a messy port setup that breaks communication

Let’s walk through this the way I actually troubleshoot it on-site.

What’s Really Happening Behind the “Offline” Status

Your Lexmark printer isn’t just sitting there idle. It constantly communicates with your system using:

• Network ports (TCP/IP or WSD)
• Local network signals (WiFi or Ethernet)
• Background services like the print spooler

Now here’s the problem…

When a firewall or antivirus steps in, it can silently block that communication. The printer is still connected. Your PC just can’t talk to it anymore.

That’s when “offline” shows up.

Real-World Signs It’s a Firewall or Port Issue

From field experience, here’s how I quickly identify it:

• Printer works fine… then suddenly stops after an update
• It prints once after restart, then goes offline again
• Other devices can print, but yours cannot
• Disabling antivirus temporarily fixes it
• Printer shows “Ready” on screen but offline on PC

If you’re seeing even two of these, you’re likely dealing with network blocking or port issues.

Step 1: Check If Firewall Is Blocking Your Printer

This is always my first move.

On Windows:

1. Open Control Panel
2. Go to Windows Defender Firewall
3. Click Allow an app through firewall
4. Enable:
   • File and Printer Sharing
   • Network Discovery

Make sure both are allowed on Private networks.

👉 Quick tip from experience:
If your network is set to “Public,” printers often get blocked automatically. Switch it to Private.

Step 2: Test by Temporarily Disabling Firewall

This is just a diagnostic step.

1. Turn off firewall briefly
2. Try printing

If it works instantly… you’ve found the issue.

Turn it back on right after testing.

Step 3: Fix Antivirus Blocking (Often Overlooked)

This one catches a lot of people off guard.

Modern antivirus tools don’t just scan files. They control network traffic too.

What I usually do:

• Open antivirus dashboard
• Look for Firewall / Network / Protection settings
• Add printer IP as trusted
• Allow spooler-related processes

👉 Advanced tip:
Some antivirus programs reset rules after updates. If your issue comes back randomly, this is usually why.

Step 4: Fix the Real Problem — Port Configuration

This is the big one. Most recurring offline issues come from this.

The Problem with WSD Ports

WSD (Web Services for Devices) sounds convenient, but in real-world use:

• It’s unstable
• Easily blocked by firewall
• Breaks after network changes

I rarely leave clients on WSD anymore.

Step 5: Switch to TCP/IP Port (Permanent Fix)

Here’s how I fix it for good:

1. Go to Devices and Printers
2. Right-click Lexmark printer → Printer Properties
3. Open Ports tab

If you see WSD, that’s your issue.

Now fix it:

1. Click Add Port
2. Choose Standard TCP/IP Port
3. Enter printer IP address
4. Complete setup
5. Select new port → Apply

👉 This alone solves most “keeps going offline” complaints I handle.

How to Find Your Printer’s IP Address

You’ll need this for port setup.

From experience, easiest methods:

• Print network configuration page
• Check router device list
• Look in printer’s onboard settings

Step 6: Lock It Down with Static IP (Pro-Level Fix)

If you want this problem gone for good, don’t skip this.

Why it matters:

Your router assigns a new IP sometimes.
When that happens → your PC looks for the old one → printer goes offline.

Fix:

• Log into your router
• Assign a static IP to your printer

Now your connection stays consistent.

Network Blocking + Port Issues (How They Work Together)

Here’s something most guides don’t explain clearly.

These two problems are connected:

• Firewall blocks communication
• WSD port fails to reconnect properly
• Dynamic IP changes break mapping

👉 Result: recurring offline issue

That’s why just “restarting” never truly fixes it.

Mac Users — Quick Practical Fix

For macOS setups I handle:

1. Remove the printer
2. Re-add using IP option
3. Use:
   • Protocol: HP Jetdirect (Socket)
   • Enter IP manually

Avoid auto-detection when dealing with offline issues.

When This Needs Expert Attention

Sometimes it goes deeper.

Call in help if:

• Printer disconnects across multiple devices
• Network has multiple routers or extenders
• Firewall rules keep resetting
• You’re unsure about port or IP setup

In those cases, remote diagnosis saves a lot of time.

Final Take from Real Experience

After years of fixing this exact issue, here’s the pattern:

• It’s rarely hardware
• It’s almost always communication blocking
• WSD ports are the biggest culprit
• Static IP + TCP/IP port is the long-term solution

Once you set that up properly, the offline issue usually doesn’t come back.

FAQs

Why is my Lexmark printer offline due to firewall?

Because your firewall is blocking network communication between your computer and printer. Allowing printer services usually fixes it.

How do I stop antivirus from blocking my printer?

Go into antivirus network settings and add your printer IP or related services as trusted exceptions.

What port should I use for Lexmark printer?

Use Standard TCP/IP port. It’s more stable than WSD and prevents recurring offline issues.

Why does my printer go offline again and again?

Most often due to dynamic IP changes or unstable WSD port configuration. Switching to TCP/IP with static IP solves it.

Can firewall updates cause printer offline errors?

Yes. Updates can reset rules, blocking your printer again without warning.

Is this a hardware issue?

No. In most cases, it’s a network or configuration issue, not the printer itself.