Status: Well-known port (0-1023)
Official assignment: Unclear/Unassigned
Historical use: Apple NetInfo (deprecated)
Current use: Rare to none
What This Port Is
Port 838 sits in the well-known port range (0-1023), which means it falls within the space that IANA reserves for system-level services. These are the ports that require root privileges to bind to on Unix-like systems—the numbers reserved for infrastructure protocols that everyone needs.
Except port 838 doesn't carry much of anything anymore.
The NetInfo Era
Some sources identify port 838 as historically associated with NetInfo—Apple's directory service system used in Mac OS X for network and system configuration in the early 2000s.12 NetInfo handled things like user accounts, network settings, and system information across Mac networks using RPC (Remote Procedure Call) mechanisms.
NetInfo was deprecated and replaced by Open Directory in Mac OS X 10.5 Leopard (released October 2007). The service has been gone for nearly two decades. Yet the port reservation remains.
Current Status
The official IANA registry status for port 838 is ambiguous. Some unofficial port databases list it as assigned to something called "DPMTF" (Desktop Protocol Management Task Force), but there's virtually no documentation about what this service actually does or whether it was ever deployed.3
In practice, you're unlikely to find anything listening on port 838 on modern systems. It's effectively unassigned—a reserved number that carries no traffic.
Why Unassigned Ports Matter
The existence of ports like 838 tells you something about the port system: not every reservation ages well.
The well-known range was established in the early Internet, when address space felt infinite and reserving a number for a specific service seemed harmless. Some of those services disappeared. Some were never widely adopted. The numbers remain.
Unassigned ports in the well-known range represent:
- Historical artifacts — Services that mattered once and don't anymore
- Failed predictions — Protocols that seemed important but never caught on
- Administrative overhead — The difficulty of reclaiming reserved numbers once assigned
Port 838 is a ghost. The service it carried is gone, but the reservation persists—a footnote in the Internet's infrastructure.
How to Check What's Listening on Port 838
If you want to verify nothing is using this port on your system:4
On Linux/macOS:
On Windows:
If something actually appears, you've found either a very old Mac system still running NetInfo (unlikely) or a service that's repurposed this port for its own use.
The Bottom Line
Port 838 exists in the well-known range but carries almost nothing. It's a reserved number tied to a deprecated Apple service from the early Mac OS X era—a reminder that the Internet's numbering system preserves history even when the services themselves are long gone.
Most ports tell you what's running. Port 838 tells you what used to run.
Frequently Asked Questions About Port 838
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