Port 99993 services

3 entries are registered on port 9999. It is a registered port (1024–49151) — IANA records an assignee, but nothing stops other software from listening here, which is why the number carries more than one entry.

entries
3

services registered on this number

transport
tcp

1 transport in use

in transit
0/3

entries encrypted on the wire

worst risk
4/10

0 of 3 iana-registered

Services on this port

ranked by lookups

01Lantronix RS-485 Telnet Controltcp · unofficial · risk 4/10

Port 9999 is commonly used by Lantronix device servers like the UDS-10 and UDS100 for remote Telnet configuration and management of serial-to-Ethernet converters, particularly those supporting RS-485 communication. This port allows network administrators to connect to the embedded Telnet service to configure network settings, serial parameters, or perform diagnostics on the device remotely.

port 9999 as Lantronix RS-485 Telnet Control

02Hydranode TELNET Controlno transport recorded · unofficial · risk 4/10

Hydranode is a modular, multi-network peer-to-peer client, with its TELNET control interface allowing remote management and diagnostics of eDonkey2000 network activity. This control channel provides commands to oversee file transfers, monitor network status, and configure client behavior.

port 9999 as Hydranode TELNET Control

03Urchin Analyticsno transport recorded · unofficial · risk 4/10

Urchin Web Analytics is a discontinued web traffic analysis software suite, historically used to analyze web server log files and provide insightful reports on website visitors, behaviors, and traffic sources. It was a popular tool for webmasters and marketers before being acquired and eventually phased out by Google in favor of Google Analytics. Port 9999 was often utilized in default setups for the Urchin administrative console or remote data collection agents.

port 9999 as Urchin Analytics

Which one is on your host

ask the machine, not the registry

The registry says what 9999 is registered to. What is listening on it right now is decided by the host, and only the host can be asked. Each of these prints the process behind the socket.

linux
ss -ltnp | grep ':9999\b'
macos
lsof -nP -iTCP:9999 -sTCP:LISTEN
windows
netstat -ano | findstr :9999

On Linux and Windows the process name comes back with the socket; on macOS lsof needs sudo to name a process that isn't yours. Match what it prints against the 3 entries above.

A port number is not a service. Anything may listen on 9999 — what you actually met is decided by the host, not the registry. If a service is missing here, it belongs in the registry.

contribute an entry