Port 3677: RoverLog IPC — the ham radio operator's reserved corner of the registry

What This Port Is

Port 3677 is registered with IANA as RoverLog IPC — the inter-process communication channel for RoverLog, a contest logging program built for VHF/UHF/Microwave amateur radio operators.¹

Tom Mayo registered the port in January 2003.²

What RoverLog Is

Amateur radio operators don't just work the HF bands you might have heard of. A dedicated community competes in VHF, UHF, and microwave contests — frequencies where antenna pointing and geography matter enormously. To maximize contacts, many operators become rovers: they load their cars with radio equipment and antennas, then drive a planned route through different geographic grid squares during the contest, activating each one.

RoverLog is the logging software built specifically for this activity. It tracks contacts, calculates scoring, and helps operators manage the complexity of operating from multiple locations across a contest weekend.³

Port 3677 is the IPC (inter-process communication) channel — the local socket where multiple instances of the application talk to each other, likely to coordinate logging across multiple radios or operator positions at the same rover station.

What Range This Port Belongs To

Port 3677 sits in the registered port range (1024–49151). These ports are available to ordinary applications and services. Unlike well-known ports (0–1023), they don't require elevated privileges to use. Unlike the dynamic/ephemeral range (49152–65535), they're meant to be stable, predictable addresses for specific applications.

IANA maintains the registry of registered ports — anyone can apply to reserve one for their application. The registry is not a curated hall of fame. It's a first-come, first-served ledger that captures everything from enterprise protocols to hobby software. Port 3677 is a fair example of the latter.

How to Check What's Using This Port

If you see traffic on port 3677 and you're not running amateur radio logging software, something else has claimed it. Check with:

macOS/Linux:

# See what process is listening
lsof -i :3677

# Or with ss (Linux)
ss -tlnp | grep 3677

Windows:

netstat -ano | findstr :3677

The PID in the output can be matched to a process name in Task Manager or with tasklist /fi "PID eq <pid>".

Why Unassigned-Looking Ports Matter

Most registered ports are occupied by software you've never heard of. The IANA registry has thousands of entries covering industrial control systems, legacy enterprise software, niche scientific tools, and yes, amateur radio logging programs. When a port number shows up in a security scan or a firewall log, it's worth checking the registry before assuming it's suspicious or assuming it's benign.

Port 3677 is a reminder: the Internet's port space is not cleanly partitioned between the famous and the empty. Most of it belongs to the specific and the forgotten.