Port 3230: Software Distributor — A Registered Port with Two Lives

What Port 3230 Is

Port 3230 sits in the registered ports range (1024–49151). These ports are not reserved by the operating system — any process can open them — but they are tracked by IANA. To use a registered port officially, you're supposed to register your service. Someone did, for this one.

IANA lists port 3230 as sftdst-port: the Software Distributor Port, registered for HP's SD-UX system.¹

The HP Software Distributor

HP Software Distributor (SD-UX) was the package management system for HP-UX, HP's proprietary Unix operating system.² Think of it as HP-UX's equivalent of what apt or rpm would eventually become on Linux — a way to install, update, and distribute software packages across managed servers from a central depot.

SD-UX ran a background daemon called swagentd, started at boot, that listened for incoming software distribution requests over TCP and UDP. Port 3230 was its registered home.³

HP-UX 10.0 shipped with SD-UX in 1995. It worked. Enterprises used it. And then the world moved on — Linux, cloud infrastructure, and modern package managers made HP-UX increasingly niche. The port remains registered. The world it was built for is mostly gone.

The Second Life: Polycom ViaVideo

Meanwhile, Polycom used ports 3230–3231 (TCP) and 3230–3235 (UDP) for its ViaVideo H.323 video conferencing system.⁴ These ports carried audio, video, and data channels for calls — the actual media streams once H.323 signaling on port 1720 had set up the connection.

The Polycom use wasn't coordinated with HP or IANA. It's simply what happened: Polycom picked a range that worked, documented it for IT administrators configuring firewalls, and shipped millions of devices. If you open port 3230 on a firewall because your video conferencing vendor told you to, that's probably why.

What Range This Port Belongs To

Registered ports (1024–49151): Ports in this range require no OS privilege to open, unlike well-known ports (0–1023) which typically need root. Any application can bind to port 3230. IANA maintains a registry of registered uses, but registration is voluntary and enforcement is nonexistent. Conflicts happen.

The registered range is where most server applications live — databases, middleware, proprietary enterprise software. It's also where you'll find the graveyard of services that were important once.

How to Check What's Listening on Port 3230

# macOS / Linux
sudo lsof -i :3230

# Linux (alternative)
sudo ss -tlnp sport = :3230

# Windows
netstat -ano | findstr :3230

If something is listening and you don't recognize it, cross-reference the process ID with your running processes. On modern systems, port 3230 traffic is almost certainly not HP Software Distributor.

Why This Port Exists in the Registry

The registered port system is a coordination mechanism, not an enforcement mechanism. IANA publishes a registry so that software authors can check what's claimed before picking a port — reducing collisions, not eliminating them. Port 3230 got claimed by HP in an era when HP-UX was a serious Unix platform. The claim is still there. The platform is not.

This is common. Hundreds of registered ports point to software nobody runs anymore. They're not reused because removing a registration could theoretically break something, somewhere, that nobody can find. So they sit, registered and dormant, while new software picks nearby numbers and hopes for the best.