Port 1475: Taligent License Manager — A ghost in the registry

Port 1475 sits in IANA's registry with the name "taligent-lm"—Taligent License Manager. Both TCP and UDP. Officially assigned. Permanently reserved.

The problem: Taligent Inc. dissolved in January 1998.

The Company That Requested This Port

Taligent was formed in 1992 as a joint venture between Apple and IBM, later joined by Hewlett-Packard. The goal was ambitious: build the next generation of object-oriented operating systems. By 1993, they had grown to more than 400 employees working on what they called Pink—a complete reimagining of how operating systems should work.

After years of shifting goals and delays, Taligent OS was canceled. The company pivoted to frameworks, released CommonPoint in 1995, then became a wholly-owned IBM subsidiary. Two years later, IBM dissolved the company entirely. The engineering teams became IBM employees. The ambitious operating system became a cautionary tale.

But the port assignment remained.

What This Port Tells Us About IANA

Port 1475 demonstrates something important about how IANA manages the port registry: assignments are permanent. When a company requests a registered port (ports 1024-49151), IANA treats it as allocating a fraction of a shared global resource. The process requires documentation, expert review, and can take 1-2 months.

Once assigned, the port stays assigned. Even when:

• The software never ships widely
• The company dissolves
• No one uses the port anymore
• Decades pass

This isn't a flaw—it's intentional. Removing port assignments would be dangerous. Old software might still be running somewhere. Network configurations might depend on those numbers. The stability of the registry matters more than reclaiming unused ports.

The Registered Port Range

Port 1475 belongs to the registered ports range (1024-49151). These ports are:

• Available through formal assignment — You can't just pick one and use it; you apply to IANA
• Reviewed by experts — Your request gets evaluated to ensure it's legitimate
• Permanently allocated — Once assigned, it's yours (or your ghost's) forever
• Not automatically enforced — Nothing technically prevents software from using port 1475 for something else, but doing so violates the registry and creates conflicts

The registered range exists between well-known ports (0-1023, which require root access) and dynamic ports (49152-65535, which applications use temporarily). It's the middle ground: official assignments for applications that don't need the elevated privileges of well-known ports.

What's Actually Using This Port?

Almost certainly nothing. Taligent's software disappeared with the company. The license manager it was meant for never became widely deployed.

You can check what's listening on port 1475 on your own system:

On Linux/Mac:

sudo lsof -i :1475
# or
sudo netstat -tulpn | grep 1475

On Windows:

netstat -ano | findstr :1475

If you see something, it's either:

1. Very old Taligent-related software (extremely unlikely)
2. Modern software that reused this port number without official approval
3. Malware or unauthorized services

SpeedGuide's port database notes that this port has been associated with security risks and trojans, likely because its official assignment is obscure enough that malicious software can use it without drawing immediate attention.

Why Unassigned Ports Matter

Port 1475 isn't truly unassigned—it's assigned to software that vanished. This makes it part of a larger category: zombie ports. Officially claimed, practically unused.

The port registry is finite. There are only 48,128 registered ports (1024-49151). Each assignment, even to a defunct company, consumes that shared resource permanently. This is why IANA's review process exists—to prevent frivolous requests from cluttering the registry with more ghosts.

But these zombie ports serve a purpose too: they're proof that the Internet's infrastructure is built for permanence. Port numbers don't get recycled like IP addresses. They don't expire like domain names. Once assigned, they exist forever in the registry—a kind of digital archaeology where you can still find traces of companies and projects that failed decades ago.