Port 1046: WebFilter Remote Monitor — A registered port for a specific purpose

Port 1046 lives in the registered ports range (1024-49151), where organizations can claim port numbers for their specific services. In 2004, it was registered for WebFilter Remote Monitor (service name: wfremotertm), a component used by web content filtering software to remotely monitor and manage Internet usage.¹

What the Registered Ports Range Means

The Internet's port space is divided into three ranges:

• Well-known ports (0-1023): Reserved for common services like HTTP, SSH, DNS. Require administrative privileges to use.
• Registered ports (1024-49151): Available for specific applications that register with IANA. Port 1046 sits here.
• Dynamic/ephemeral ports (49152-65535): Used temporarily by client applications for outbound connections.

When a company builds network software, they can request a registered port from IANA to ensure their service doesn't conflict with others. This is what happened with port 1046.

WebFilter Remote Monitor

WebFilter Remote Monitor was designed for corporate web content filtering—blocking unwanted websites and monitoring employee Internet usage. The remote monitoring component allowed administrators to track and control web access on computers outside the corporate network.²

Web filtering was (and remains) a common need: companies want to block malicious sites, enforce acceptable use policies, and monitor bandwidth consumption. WebFilter was one of many products solving this problem in the early 2000s.

The port was registered to Tim Morgan in November 2004, indicating someone thought the service would become widespread enough to warrant its own permanent port number.³

Why You Probably Don't See It

Despite being officially registered, port 1046 isn't commonly encountered today. Most web filtering has moved to different architectures:

• Cloud-based filtering: Modern solutions like Cisco Umbrella or Zscaler filter at the DNS or proxy level, not requiring specific client ports
• Browser extensions: Many filtering systems now work as browser plugins
• VPN-based filtering: Remote workers connect through VPNs that enforce policies without client-side monitoring software

The registered ports range is full of ports like this—claimed for specific products that existed, worked, maybe even mattered to someone's business, but never became ubiquitous enough for most network administrators to recognize the port number.

Security Considerations

If you see unexpected traffic on port 1046:

Check what's using it:

# Linux/macOS
sudo lsof -i :1046
sudo netstat -tulpn | grep 1046

# Windows
netstat -ano | findstr :1046

Verify the process: If something is listening on port 1046, identify the process. It could be:

• Legitimate web filtering software (if your organization uses it)
• A different application that happened to choose this port
• Malware using a less-common port to avoid detection

Firewall rules: If you're not running web filtering software, there's no reason for port 1046 to be open. Block it at the firewall if you're concerned.

The Reality of Registered Ports

Port 1046 represents a common pattern in the registered range: someone built a product, registered a port with IANA, deployed it to some number of customers, and then either the product evolved to not need the port anymore, was replaced by newer technology, or simply never achieved widespread adoption.

The IANA registry contains thousands of these ports—each one a small piece of Internet history, a record that someone once thought their application would matter enough to claim a permanent address in the global port namespace.

How to Check What's on Port 1046

If you want to see if anything is listening on port 1046 on your system:

# Scan your local machine
nmap -p 1046 localhost

# Check if something is listening
# Linux/macOS: sudo lsof -i :1046
# Windows: netstat -ano | findstr :1046

Most likely, you'll find nothing. Port 1046, like many registered ports, sits unused on most systems—reserved but empty, waiting for a service that may never arrive.

Related Ports

Other ports in the web filtering and monitoring space include:

• Port 3128: Squid proxy (common for web filtering and caching)
• Port 8080: Alternative HTTP port (often used by web proxies)
• Port 8443: Alternative HTTPS port (used by some web management interfaces)