Port 1694: rrimwm — A Name Without a Story

What Port 1694 Is

Port 1694 sits in the registered port range (1024–49151). These ports are coordinated by IANA — the Internet Assigned Numbers Authority — which maintains the official registry of which port numbers are assigned to which services. Unlike the well-known ports (0–1023), registered ports don't require root privileges to use, and they're typically claimed by specific applications rather than foundational Internet protocols.

IANA lists port 1694 as assigned to a service named rrimwm, on both TCP and UDP.¹ That's the entirety of the official record. No description. No RFC. No contact. No software that publicly identifies itself as rrimwm.

The acronym doesn't appear in any published technical standard, open-source project, or vendor documentation. Whatever "rrimwm" stood for — and whoever registered it — left no other footprint.

What This Means in Practice

Port 1694 is effectively unoccupied. The registration exists, but registered ports carry no enforcement: any application can open any port, and a name in the IANA registry is a courtesy reservation, not a lock. If you see traffic on port 1694, it almost certainly isn't "rrimwm" — it's whatever software on your system decided to use that number.

Common reasons a port like this shows up on a machine:

• A dynamic application chose it opportunistically (many apps pick available registered ports at install time)
• A development or testing service bound to it temporarily
• Malware using an obscure port to avoid attention (unlikely but worth noting)

How to Check What's Listening

If you see activity on port 1694 and want to know what's actually using it:

On Linux or macOS:

# Show what process is listening on port 1694
ss -tlnp | grep 1694
# or
lsof -i :1694

On Windows:

netstat -ano | findstr :1694

The process ID in the output can then be looked up in Task Manager or with tasklist /fi "pid eq [PID]" to identify the software.

Why Unassigned-in-Practice Ports Matter

The registered port range contains thousands of entries like this — names that were claimed, then abandoned or never deployed publicly. They matter for a few reasons:

Firewall policy. A port with no known legitimate use is easier to block without consequences. If 1694 shows up in your firewall logs, the absence of a known service is itself useful signal.

Security scanning. Port scanners flag open ports against expected services. An open port 1694 with no known referent is a prompt to investigate — not because "rrimwm" is dangerous, but because something is there and you should know what it is.

The registry as archaeology. The IANA port registry is a partial record of computing history — protocols that thrived, protocols that died, and registrations that simply never led anywhere. Port 1694 is one of the quiet ones.