Port 826 — Unassigned in the well-known range

What Port 826 Is

Port 826 is unassigned. It sits in the well-known ports range (0-1023)—the space reserved for fundamental Internet protocols—but has no official service assigned to it.¹

This is unusual. The well-known ports range is supposed to be carefully curated, with ports assigned only to protocols important enough to warrant system-level status. Port 826 being empty means that in over 50 years of Internet history, no protocol has been deemed important enough to claim this number.

The Well-Known Ports Range

Ports 0-1023 are called well-known ports or system ports. They're assigned by IANA through strict processes—typically requiring IETF review or IESG approval.² On Unix-like systems, you need superuser privileges to bind a service to these ports.

This range includes the protocols that make the Internet work:

• Port 80 (HTTP) - Web traffic
• Port 443 (HTTPS) - Encrypted web traffic
• Port 25 (SMTP) - Email transmission
• Port 53 (DNS) - Name resolution

Port 826 shares the same prestigious range, but carries nothing.

Why Unassigned Ports Exist

Not every port number in the well-known range has a service. There are gaps—ports that were never assigned, or were assigned to protocols that faded into obsolescence and had their assignments removed.

According to IANA records, port 826 falls within the range 811-827, which is marked as unassigned.³ These gaps serve several purposes:

Future allocation - New fundamental protocols can be assigned well-known port numbers without having to renumber existing services

Range boundaries - Some unassigned ports exist at the edges of ranges, potentially available to extend the port number space if needed⁴

Historical artifacts - Some ports were never assigned simply because no protocol requested them

Checking What's Using Port 826

Even though port 826 has no official assignment, something could still be listening on it. To check:

On Linux or macOS:

sudo lsof -i :826
# or
sudo netstat -an | grep :826

On Windows:

netstat -ano | findstr :826

If something appears, it's either:

• A misconfigured service using the wrong port
• Custom software that chose an unassigned port
• Potentially malicious software trying to hide in an unexpected place

The Gap in the Map

The well-known ports range is a map of Internet infrastructure. Each assigned port is a door to a specific protocol, a specific purpose. Port 826 is a space on that map with no label, no building, no purpose.

It's not broken. It's not reserved for something secret. It's just... empty. A reminder that even in a carefully designed system, there are numbers that go unused.