Port 822 has no official service assignment. Despite sitting in the prestigious well-known range, nobody has claimed this number.
The Well-Known Range
Ports 0-1023 are called "well-known ports" because IANA (the Internet Assigned Numbers Authority) tightly controls them. These are the ports reserved for fundamental Internet services—the ones that needed to be standardized so everyone could find them.
Port 22 is SSH. Port 80 is HTTP. Port 443 is HTTPS. Everyone knows where to find these services because the port numbers never change.
Port 822 sits in this range, but it's empty.
What "Unassigned" Means
When IANA marks a well-known port as unassigned, it means:1
- No protocol has officially claimed this number
- No RFC defines a service for this port
- The number is available for future assignment
- Organizations can request it through IANA's application process
The well-known range isn't completely full. There are gaps. Port 822 is one of them.
Why Gaps Exist
Not every well-known port got assigned immediately. Some were reserved in the 1980s for protocols that never became popular. Others were simply skipped. Port assignments happened organically as protocols were created, not systematically from 0 to 1023.
The result: a numbering system with holes. Port 821 is unassigned. Port 822 is unassigned. Port 823 is unassigned. Three numbers in a row, all unclaimed.
Checking What's Actually Listening
Just because a port is officially unassigned doesn't mean nothing could be using it on your machine. Some software uses unassigned ports for custom services.
On Linux/Mac:
On Windows:
If something appears, you've found a service using an unassigned number—perfectly legal on a private network, just not standardized for the Internet.
Security Considerations
Unassigned ports are generally safer than assigned ones in one sense: automated scans usually target known services on assigned ports. An attacker looking for SSH tries port 22. They're less likely to probe port 822 randomly.
That said, running a sensitive service on an unassigned port isn't security through obscurity—it's just obscurity. If you're running something on port 822, secure it properly regardless of the port number.
The Port Assignment Process
If you're building a protocol and need an official port number, IANA has an application process.2 For well-known ports (0-1023), you need:
- A protocol specification (usually an RFC)
- A legitimate reason why your protocol needs a well-known port
- IETF review and approval
Most new protocols don't qualify. The well-known range is reserved for fundamental Internet infrastructure, not application-specific services. Those typically get registered ports (1024-49151) instead.
Port 822 sits waiting. Maybe someday someone will request it. Maybe it'll remain a gap forever.
Related Ports
- Port 821 — Unassigned
- Port 823 — Unassigned
- Ports 0-1023 — The well-known range (most assigned, some gaps remain)
Frequently Asked Questions
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