Port 3450: CAStorProxy — The Registered Port Nobody Remembers

What Port 3450 Is

Port 3450 sits in the registered ports range (1024–49151), the block that IANA assigns to specific services when a vendor or developer formally requests one.

It has a registration. IANA lists it as CAStorProxy — assigned in April 2002 to someone named Raymond J. Young, covering both TCP and UDP.¹ What CAStorProxy actually was is almost entirely undocumented. No RFC was published. No product documentation survives. The name suggests a storage proxy of some kind, but the trail goes cold there.

This happens. IANA registered the port, the product never achieved widespread use (or was abandoned), and the port number quietly became available for other things to claim informally.

What Actually Uses Port 3450

TrackMania Forever (and related titles)

The most documented use is TrackMania Forever and TrackMania Nations Forever — the racing games from Nadeo. When running a dedicated server or hosting peer-to-peer multiplayer sessions, these games use:

• Port 2350 for server connections
• Port 3450 for P2P (peer-to-peer) connections between players²

Both TCP and UDP. If you're troubleshooting a TrackMania server that won't let friends connect, this is the port you need to forward.

Other Reported Uses

Port databases also list Virtual Places Voice Chat and Virtual Skipper 5 (a sailing simulation game) as historical users of this port.³ Both are niche enough that encounters in the wild are rare.

Security scanners have flagged port 3450 in the context of proxy trojans — malware that opens a proxy listener on this port to route traffic through an infected machine. Worth knowing if you see unexpected activity here.

Why Unassigned-in-Practice Ports Exist

The registered ports range contains 48,128 port numbers. IANA has assigned a fraction of them. The rest are either unregistered or, like port 3450, registered to services that never became widely known.

This creates a gray zone that software developers exploit constantly. When an application needs a port for internal communication, P2P gaming, or a custom protocol, developers often pick something in the registered range that doesn't conflict with anything they care about. Nobody checks the IANA list first. The result is a layer of unofficial assignments living on top of official ones — and port databases like SpeedGuide and GRC's Port Authority exist partly to track this reality.

How to Check What's on This Port

If port 3450 shows up in your network logs and you want to know what put it there:

Linux / macOS:

# Which process is listening on port 3450?
sudo ss -tlnp | grep 3450
sudo lsof -i :3450

Windows:

# Show listening ports with process IDs
netstat -ano | findstr :3450

# Look up the process ID
tasklist | findstr <PID>

What to expect: If you have TrackMania installed, it's almost certainly that. If you don't — and something is listening — that's worth investigating.