Port 941 sits in the well-known port range (0-1023), reserved by IANA for fundamental Internet services. But if you check what's listening on port 941 on a modern system, you'll find nothing. This port was assigned to a service that no longer exists.
What Used to Run Here
Port 941 was part of the port range (600-1023) used by Mac OS X for RPC-based services, specifically NetInfo—a distributed directory service that stored network configuration data.1
NetInfo managed administrative information: user accounts, groups, network settings, printer configurations, and other system resources. It was hierarchical and distributed, allowing Mac OS X systems to share configuration across networks.2
The NetInfo Story
NetInfo wasn't originally Apple's creation. It came from NeXT, introduced in NeXTSTEP version 0.9 to replace both Unix configuration files and Sun's Network Information Service (Yellow Pages).3
When Apple acquired NeXT in 1997 and built Mac OS X on NeXTSTEP's foundation, NetInfo came along for the ride. It was built into Mac OS X from the beginning in 2000.3
But NetInfo had problems. DNS queries ran through NetInfo, which meant basic system tasks could stall if NetInfo got stuck on a DNS lookup. When DNS failed, the entire NetInfo service could grind to a halt and lock users out.3
Apple began replacing NetInfo with Open Directory—based on the standard Lightweight Directory Access Protocol (LDAP)—starting with Mac OS X Server 10.2 Jaguar in 2002. By Mac OS X 10.5 Leopard in 2007, NetInfo was completely removed from both client and server versions.34
What This Port Means Now
Nothing uses port 941 in modern systems. NetInfo is gone. But the port number remains in the well-known range—a reserved address for a service that vanished.
This is genuinely unusual. Most well-known ports carry protocols that lasted decades: SSH on 22, HTTP on 80, DNS on 53. These are foundational services that survived because they solved problems that didn't go away.
Port 941 carried a service Apple replaced entirely. It's a historical artifact—evidence of an architectural decision that didn't work out.
Checking What's Listening
You can check if anything is using port 941 on your system:
On macOS/Linux:
On Windows:
On a modern Mac, you'll find nothing. The port is silent.
Why Unassigned Ports Matter
Port 941 isn't technically unassigned—it was assigned to NetInfo. But since NetInfo no longer exists, the port sits unused in the most privileged range.
The well-known port range (0-1023) requires root/administrator privileges to bind to. These ports were meant for essential services that needed protection from unprivileged programs. Port 941 has that privileged status, but nothing to protect anymore.
Unassigned or abandoned ports like this show how the Internet's infrastructure evolves. Services disappear. Protocols get replaced. But the port numbers—those 16-bit addresses that determine where packets go—remain in the registry, permanent records of what once ran on the network.
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