Port 844 sits in an unusual position. It lives in the well-known ports range (0-1023)—the prestigious neighborhood where fundamental Internet protocols like HTTP, SSH, and DNS reside—but it has no official assignment.1
According to IANA (Internet Assigned Numbers Authority), port 844 falls within the unassigned range of 834-846. No RFC defines it. No protocol claims it. No service has registered it as their home.
What "Unassigned" Means
The well-known ports range is heavily regulated. Ports in this range require IETF Review or IESG Approval to be officially assigned.2 These ports are meant for standardized services that need universal recognition.
Port 844 has been reserved but never claimed. It's a number waiting for a purpose.
Why This Matters
Unassigned doesn't mean unused. Any application can technically listen on port 844. You might find:
- Custom enterprise applications
- Development servers
- Legacy software from organizations that chose this port before formal registration mattered
- Nothing at all
Some third-party port databases claim port 844 was used for "Mac OS X RPC-based services" or NetInfo,3 but Apple's official documentation makes no mention of port 844.4 These claims appear to be historical confusion or outdated information.
Checking What's Listening
If you need to see what's actually using port 844 on your system:
On Linux/macOS:
On Windows:
If nothing responds, the port is closed—which is the expected state for an unassigned port.
The Gaps in the Map
The Internet's port system has 65,535 possible numbers. Not all of them need to be assigned. Ranges like 834-846 exist as breathing room—numbers held in reserve for future protocols that haven't been invented yet, or services that haven't needed formal standardization.
Port 844 is part of that reserve. It's not a failure or oversight. It's the system working as designed: not every number needs immediate purpose.
Security Considerations
Since port 844 has no standard service, any traffic on this port should be investigated:
- Legitimate custom applications should be documented in your network inventory
- Unexpected listeners might indicate unauthorized software
- Firewall rules should block this port unless you specifically need it open
The absence of a standard service makes anomaly detection easier. If you see port 844 traffic and don't know why, that's worth investigating.
Related Ports
Port 844 sits among other unassigned neighbors:
- Ports 834-843: Unassigned
- Ports 845-846: Unassigned
The nearest assigned ports:
- Port 833 (TCP/UDP): Previously used for NETCONF over BEEP (deprecated)
- Port 847 (TCP/UDP): DHCP Failover protocol
Frequently Asked Questions About Port 844
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