can i use my hp laserjet m234dwe printer with a vpn turned on? it keeps dropping off the network.

Diagnosis

The HP LaserJet Pro MFP M234dwe relies on a persistent local network handshake to maintain its connection to your PC or mobile device. When you activate a VPN (Virtual Private Network), the software creates an encrypted tunnel that reroutes your internet traffic. In many default configurations, the VPN implements a "kill switch" or a strict firewall rule that disables "Local Network Access." This essentially hides your local subnet from your computer, making the printer invisible even though both devices are physically connected to the same Wi-Fi router.

This manifests as the printer appearing "Offline" in the Windows Print Queue or the HP Smart app immediately after the VPN connects. Because the M234dwe uses a dynamic IP address by default, any shift in the network routing table caused by the VPN prevents the computer from locating the printer's specific IP address. You can confirm this is the issue by attempting to ping the printer's IP address in the Command Prompt while the VPN is active; if the request times out but works while the VPN is off, the VPN is blocking the local route.

How to Fix It

To use your printer while maintaining your VPN connection, you must enable a feature called "Split Tunneling" or "Allow Local Network Access." This allows the computer to communicate with local devices (like your printer) while sending secure data through the VPN tunnel.

1. Open your VPN client software (e.g., NordVPN, ExpressVPN, Cisco AnyConnect) and navigate to the Settings or Preferences menu.
2. Locate the Connection or Advanced tab.
3. Find the toggle labeled "Allow local network access" or "Invisibility on LAN". Ensure "Allow local network access" is turned ON and "Invisibility" is turned OFF.
4. If your VPN uses a "Kill Switch," check if there is a setting for "Local Network Exclusion" and enable it.
5. Restart your computer to flush the DNS cache and re-establish the local routing table.
6. Open the HP Smart app and verify the printer status is "Ready."

If That Didn't Work

• Assign a Static IP Address: The M234dwe often drops off because the router assigns a new IP via DHCP. Access the printer's Embedded Web Server (EWS) by typing the printer's IP address into a web browser. Go to Networking > IPv4 Configuration, change the assignment from "Automatic/DHCP" to "Manual," and set a permanent IP address (e.g., 192.168.1.150). This prevents the VPN from "losing" the printer when the lease expires.
• Disable "Client Isolation" on Router: Some modern routers have a security feature called AP Isolation or Guest Mode that prevents wireless devices from talking to each other. Log into your router's admin panel and ensure "AP Isolation" is disabled for the band your printer is using.
• Use a Wired Ethernet Connection: While the M234dwe is primarily wireless, if you are using a laptop with a dock, try connecting the printer via USB. A direct USB connection bypasses the network layer entirely, meaning the VPN cannot interfere with the print spooler.
• Create a Firewall Exception: In Windows Defender or your third-party antivirus, manually add an "Inbound Rule" for the printer's IP address. Set the action to "Allow the connection" for all ports to ensure the VPN's firewall isn't blocking the specific ports HP uses for bidirectional communication (typically port 9100 and 631).

Heads Up

• HP+ Account Requirements: Since the M234dwe is an "e" series printer, it requires a constant internet connection to verify HP+ status. If your VPN blocks all non-tunnel traffic, the printer may enter an "Error" state because it cannot reach the HP cloud servers.
• Firmware Updates: Regularly check for firmware updates via the HP Smart app. HP frequently releases patches that improve Wi-Fi stability and compatibility with modern network protocols.
• Avoid 2.4GHz/5GHz Switching: Ensure your printer is locked to the 2.4GHz band if your router uses "Smart Connect." Frequent band-steering can cause the printer to disconnect, which is often misdiagnosed as a VPN issue.
• Sleep Mode: If the printer stays offline for too long, it may enter a deep sleep. Wake it up manually using the power button before attempting to print while the VPN is active to trigger a fresh network handshake.