Port 329: Unassigned — A Door Without a Service

Port 329 exists in the well-known ports range, but no protocol has ever claimed it. Both TCP and UDP on port 329 remain unassigned by IANA (Internet Assigned Numbers Authority). Ports 325-332 sit together in this unassigned state, a quiet neighborhood in the Internet's addressing system.¹

What "Unassigned" Means

The Internet's 65,535 ports are divided into three ranges:

• Well-Known Ports (0-1023): System ports assigned by IANA through strict IETF review
• Registered Ports (1024-49151): User ports available for registration
• Dynamic Ports (49152-65535): Ephemeral ports for temporary connections

Port 329 sits in the well-known range, which means getting it assigned requires jumping through significant hoops. You have to document why a registered port won't work for your protocol. You have to document why a dynamic port won't work. The bar is high.²

Because port 329 is unassigned, it's available. Some protocol designer could request it tomorrow through IANA's formal procedures. But after decades of Internet history, port 329 remains unclaimed.

The Well-Known Range

Well-known ports exist because certain services need consistent, predictable addresses. HTTP needs port 80. HTTPS needs port 443. SSH needs port 22. When you connect to a web server, your browser knows where to knock.

But the well-known range has 1,024 addresses, and the Internet didn't need all of them. Hundreds remain unassigned. They represent capacity, flexibility, room for protocols not yet imagined.

Port 329 is one of those reserved possibilities.

Port States in the Well-Known Range

A port in the system range can exist in three states:²

1. Assigned - Currently allocated to a specific service
2. Unassigned - Available for assignment through proper procedures
3. Reserved - Held for special purposes (extending ranges, future use, or when only TCP or UDP is assigned)

Port 329 is unassigned, not reserved. The distinction matters. Reserved ports have a reason for their unavailability. Unassigned ports are simply waiting.

Checking What's Listening

Even though port 329 has no official assignment, something could be listening on it on your system. Applications can bind to any port. To check what's actually listening on port 329:

On Linux or macOS:

# Using netstat
sudo netstat -tulpn | grep ':329'

# Using lsof
sudo lsof -i:329

On Windows:

netstat -ano | findstr ":329"

These commands show if any process has claimed port 329 on your machine. The lack of official assignment doesn't prevent local use.³

Why Unassigned Ports Matter

The existence of unassigned ports in the well-known range reveals something about Internet architecture: conservative allocation. IANA didn't hand out well-known ports freely. They created a system with room to grow, with space for protocols that might emerge decades later.

Port 329 has been unassigned since the well-known port system was formalized. It might stay unassigned forever. Or someone might need it tomorrow for a protocol we haven't imagined yet.

That's the point of unassigned ports. They're not empty space. They're possibility space.

The Bureaucracy of Port Assignment

Getting a system port assigned requires documentation, review, and approval from the IETF or IESG. You must prove that your protocol genuinely needs a well-known port—that the registered and dynamic ranges won't suffice.²

This bureaucratic friction is intentional. Well-known ports are a finite, valuable resource. The high bar for assignment keeps them from being wasted on services that don't genuinely need global, consistent addresses.

Port 329 waits behind that bureaucratic wall, unclaimed and available.

What Runs Here

Nothing. Port 329 carries no standard protocol. If you see traffic on port 329, it's either a misconfiguration, a custom application, or something unofficial.

The official answer for "what runs on port 329" is: nothing yet.

The Quiet Ports

Walk through the well-known range and you'll find clusters of famous ports—22 (SSH), 25 (SMTP), 53 (DNS), 80 (HTTP), 443 (HTTPS)—surrounded by long stretches of unassigned addresses. Port 329 sits in one of those quiet stretches.

These unassigned ports don't generate headlines. They don't carry the world's email or web traffic. They exist as infrastructure—as addressing capacity held in reserve.

Port 329 is a door without a service. A number without a protocol. An address waiting for a purpose that may never come.

And that's genuinely okay.