Port 2934: Registered, Obscure, and Surprisingly Occupied

What This Port Is

Port 2934 sits in the registered ports range (1024–49151). This is the middle tier of the port numbering system: above the well-known system ports (0–1023) that require root/administrator privilege, but below the ephemeral ports (49152–65535) that operating systems hand out automatically for outgoing connections.

Registered ports can be claimed through IANA, but claiming one doesn't mean anyone uses it — and not claiming one doesn't stop someone from using it.

The Official Assignment: 4-TIER OPM CLI

IANA lists port 2934 as assigned to 4-TIER OPM CLI — the command-line interface for a four-tier operations and management system, registered by Francois Peloffy. Both TCP and UDP are registered.¹

What is 4-Tier OPM? That's genuinely unclear. The registration exists; the software doesn't appear to. This happens regularly in the IANA registry: a company registers a port for an internal or commercial tool, the tool fades or never shipped publicly, and the port number sits reserved in perpetuity. The registry is a graveyard as much as a directory.

The Actual Use: Falcon BMS

In practice, port 2934 (alongside port 2935) is most commonly seen in port-forwarding guides for Falcon 4 BMS — a community-maintained version of Falcon 4.0, the 1998 F-16 flight simulator published by MicroProse.²

Falcon BMS uses a peer-to-peer multiplayer model. When players host or join a session, the sim needs direct UDP connectivity between participants. Routers that don't forward ports 2934 and 2935 force all traffic to route through a relay, adding latency and load. The fix is the same one gamers have been doing since the 1990s: manually forward UDP 2934 and 2935 to your machine.³

That a game from 1998 still has active multiplayer communities forwarding specific ports in 2026 says something. The sim is detailed enough — realistic enough — that its community never moved on. The ports are part of the muscle memory.

How to Check What's Listening on Port 2934

# Linux/macOS
sudo ss -tlnp | grep 2934
sudo lsof -i :2934

# Windows
netstat -ano | findstr :2934

If you're seeing traffic on this port and not running Falcon BMS, it's worth investigating. The 4-TIER OPM CLI isn't something you'd encounter in the wild, and unexpected listeners on registered ports can indicate misconfigured software or something less benign.

Why Unassigned (and Under-Used) Ports Matter

The registered port space has roughly 48,000 slots. IANA has formally assigned a few thousand. The rest are technically fair game for any application — and many software packages pick ports informally, without registering.

Port 2934 illustrates the gap between the registry and reality. On paper, it belongs to an enterprise tool. In practice, it belongs to a virtual cockpit at 30,000 feet over the Korean Peninsula.