Port 2353: Unassigned — Available in the Registered Range

What Range This Port Belongs To

Port 2353 falls in the registered ports range (1024–49151). This range sits between the well-known ports below 1024 — which belong to core Internet infrastructure like HTTP, DNS, and SSH — and the ephemeral ports above 49151, which operating systems hand out temporarily to outbound connections.

Registered ports can be claimed. Organizations and developers apply to IANA to officially associate a service name with a port number. Once registered, that port is documented in the Service Name and Transport Protocol Port Number Registry¹ and listed as belonging to that service.

Port 2353 has not been claimed. It is unassigned.

The "pspserver" Label

Some port databases list port 2353 as "pspserver." The trail goes cold quickly.

There is no IANA registration for "pspserver" at this port. The label most likely originates from early PSP (PlayStation Portable) ad-hoc networking tools — software that let PSP consoles connect to each other over local networks. Some emulators and unofficial relay servers for PSP multiplayer may have used or experimented with this port.

The PPSSPP emulator's ad-hoc server, the most prominent PSP networking project, uses TCP port 27312 as its primary port — not 2353.² Whatever "pspserver" means here, it is not an officially documented or currently active standard.

This is a common phenomenon in port documentation: one database assigns an informal label, other databases copy it, and the label accretes authority it never earned. Port 2353 is a good example. The label is not false exactly — someone, somewhere, used this port for something PSP-related — but it is also not meaningful enough to plan around.

Security Note

Some security scanners flag port 2353 as having historical malware association. This is a low signal. Malware has used nearly every port number at some point. An unassigned port with no active legitimate service is, if anything, a reasonable choice for anyone who does not want their traffic confused with known services. Finding activity on port 2353 is worth investigating — but the port number itself is not an indicator of compromise.

How to Check What's Listening

If port 2353 is open on a machine you care about, find out what put it there:

On Linux or macOS:

# See what process is listening on port 2353
sudo ss -tlnp | grep 2353
# or
sudo lsof -i :2353

On Windows:

# Show listening ports with process IDs
netstat -ano | findstr :2353
# Then look up the PID
tasklist | findstr <PID>

If something is listening, the process name will tell you more than the port number ever could.

Why Unassigned Ports Matter

The registered range contains 48,128 ports. Fewer than a few thousand have IANA assignments. The rest — including port 2353 — are available.

This availability is not a gap or a mistake. It is the design. Internal services, development tools, custom protocols, proprietary software — all of it runs on ports that were never assigned to anything else. When you spin up a development server, a game server, or a custom API, you are almost certainly using a port that IANA has never heard of.

Unassigned ports are not empty. They are free.