Port 1838: TALNET — Registered, but Unexplained

What Port 1838 Is

Port 1838 sits in the registered ports range (1024–49151). These ports are officially managed by IANA, the Internet Assigned Numbers Authority. Anyone can apply to register a port for a specific service, and IANA will add it to the registry — a record, not an endorsement.

Port 1838 is registered to a service called TALNET, attributed to a person named Aaron Lav.¹ IANA lists it for both TCP and UDP. That is the entirety of the public record.

There is no RFC. No specification. No known software. No documentation of what TALNET does, why it was created, or whether it was ever deployed. The name suggests a possible blend of "Talker" and "Telnet" — perhaps an old chat protocol concept — but that is speculation, not fact.

A registered port with no explanation is almost indistinguishable from an unregistered one.

Security History

Port 1838 has appeared in historical trojan and malware port databases.² This is worth noting, but not alarming on its own. Malicious software often uses arbitrary high-numbered ports to avoid detection, and port lists from the early 2000s flagged thousands of ports this way. The presence on a list does not mean current risk — it means that at some point, something suspicious communicated here.

If you see unexpected traffic on port 1838, investigate. Don't assume. The question is always: what process is actually listening?

How to Check What Is Using This Port

If you see port 1838 open on a system and want to know why:

On Linux or macOS:

# See what process is listening on port 1838
ss -tlnp | grep 1838
# or
lsof -i :1838

On Windows:

netstat -ano | findstr :1838
# Then look up the PID in Task Manager, or:
tasklist | findstr <PID>

The process name and path will tell you whether this is something you installed intentionally or something worth investigating further.

Why Unassigned (and Ghost-Registered) Ports Matter

The registered ports range exists so that software can claim a consistent home. When a well-known application always uses port 5432 (PostgreSQL) or port 6379 (Redis), firewalls can be configured accurately, documentation makes sense, and administrators know what to expect.

When a port is registered but never documented — or claimed by malware — it creates noise. Security teams have to spend time on ports like 1838 precisely because the registry entry offers no signal. Is this legitimate traffic? Is it an old service nobody remembers? Is it something hostile?

The honest answer for port 1838: unknown. If you encounter it in the wild, treat it as you would any unexpected open port — with curiosity and a process lookup.