Port 1406 is officially registered to NetLabs License Manager (netlabs-lm), a license verification system from the early days of commercial software distribution.1 It operates on both TCP and UDP.
This is one of thousands of registered ports that tells a story about how the Internet grew up. In the 1990s, companies building network software would register port numbers with IANA the way you'd reserve a phone number. Port 1406 belongs to NetLabs—a company that was acquired by Seagate Technology in 1995 and disappeared into the consolidation wave that defined that era.2
What This Port Was For
License managers in the 1990s worked differently than today's cloud-based activation systems. When you bought enterprise software, it came with a license server that ran on your network. Every time someone launched the application, their computer would connect to the license server to verify they had permission to use it.
Port 1406 was NetLabs' designated channel for those "can I run this software?" conversations. The client would knock on port 1406, the license manager would check its database, and either grant or deny access.
It was local. It was permanent. And when the company disappeared, the port assignment stayed in the registry.
The Registered Ports Range
Port 1406 lives in the registered ports range (1024-49151). These are ports that IANA assigns to specific services when a company or organization requests them. Unlike well-known ports (0-1023), which require root privileges and are reserved for fundamental protocols, registered ports are available to any service that asks.3
The registration system was meant to prevent conflicts—if everyone picked random ports, software would collide constantly. But it created a different problem: the registry filled up with ports assigned to services that no longer exist.
Why You'll Probably Never See This Port
NetLabs License Manager isn't widely deployed anymore. The company was absorbed into Seagate's software division in the mid-1990s, and license management evolved beyond dedicated network ports. Modern software uses HTTPS, cloud APIs, and cryptographic activation instead of port-specific license servers.
But port 1406 remains registered. The IANA registry is forever. Once a port is assigned, it stays assigned—even when the service dies, the company vanishes, and nobody remembers what it was for.
This is the reality of the registered ports range: it's part living directory, part archaeological record.
How to Check What's Actually Using Port 1406
Just because a port is registered to a specific service doesn't mean that's what's actually running on it. On your own network, anything could be listening on 1406.
To check what's using port 1406 on your system:
On Linux or macOS:
On Windows:
If something's there, it's probably not NetLabs License Manager. It might be custom software that picked an unused port. It might be malware that chose a random registered port hoping to blend in. Or it might be nothing at all.
Why Unassigned and Ghost Ports Matter
The port number system only works if everyone agrees on what the numbers mean. Well-known ports (like 80 for HTTP or 443 for HTTPS) have that agreement—every web server uses them, every browser expects them.
But in the registered range, the agreement is weaker. Port 1406 is officially for NetLabs License Manager, but nobody enforces that. You can run whatever you want on it. The registration is more like a claim than a rule.
This creates two categories of registered ports:
- Active registrations — Ports where the registered service is still widely used (like 3306 for MySQL)
- Ghost registrations — Ports where the service is extinct but the registry entry remains
Port 1406 is a ghost. The registration exists. The service doesn't. And that's fine—the Internet is big enough to hold both the living and the dead.
Related Ports
Other ports from the early license management era:
- Port 744 — Flexible License Manager (FlexLM), one of the few license manager protocols still in use
- Port 27000-27009 — FlexLM's extended range for vendor daemons
- Port 1025 — Network Blackjack, another forgotten registration from the same era
Frequently Asked Questions About Port 1406
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