Port 2864: AstroNova Main — The Data Recorder's Command Channel

Port 2864 is a registered port — officially assigned by IANA to AstroNova, Inc. under the service name astronova-main.¹ AstroNova (formerly Astro-Med, Inc.) manufactures data recorders, chart recorders, and test and measurement systems used in aerospace, defense, and industrial applications.²

The official IANA description is three words: main 5001 cmd. That tells you almost nothing — it suggests a command channel (cmd) associated with port 5001, but AstroNova has not published public documentation for the protocol. This is common for hardware vendors who register ports for proprietary device communication.

What This Port Is For

AstroNova's devices — like the TMX-18 high-speed data acquisition recorder — connect to computers for configuration, control, and data transfer. Port 2864 appears to be part of that device management layer: a channel for sending commands to the hardware.

You won't find this port in active use unless you're in a lab, test facility, or manufacturing environment running AstroNova equipment. It's not Internet-facing infrastructure. It's the kind of port that exists quietly in specialized environments and never shows up anywhere else.

What Range This Port Belongs To

Port 2864 sits in the registered port range (1024–49151). These ports are:

• Assigned by IANA upon request from organizations
• Not reserved for system use (unlike well-known ports 0–1023)
• Not assigned dynamically (unlike ephemeral ports 49152–65535)

Any application can use a registered port without elevated privileges. IANA registration means the port has an official owner, but it doesn't prevent other software from using the same port on a given machine.

If You See This Port Open

On a machine unrelated to AstroNova hardware, an open port 2864 is almost certainly something else — software that picked this number arbitrarily, a misconfiguration, or in rare cases, a process worth investigating.

To see what's listening:

macOS / Linux:

sudo lsof -i :2864
sudo ss -tlnp sport = :2864

Windows:

netstat -ano | findstr :2864
# Then check the PID:
tasklist | findstr <PID>