Port 5543QF-Test License Server

TCP port 5543 is assigned to the QF-Test License Server from Quality First Software GmbH.

transport: tcp
in transit: cleartext
assignment: official
risk: 1/10
lookups: 0

also known as qftest-licserve

Technical Details

what runs on :5543

QF-Test License Server is registered on port :5543 over tcp to Quality First Software GmbH, assigned January 2024. We don't have a technical write-up for it beyond the IANA registry entry.

In nmap's internet-wide scan data this port is never observed open, so if it's open on your network it's more likely a custom or misconfigured service than the registered one.

find what's listening on :5543

this machine

# linux
sudo ss -tlpn 'sport = :5543'

# macos / bsd
sudo lsof -nP -i :5543

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :5543

another host

nmap -sV -p T:5543 <host>

run it? the handshake, the implementations you meet in the wild and the flags that matter come from the engineers who do.

add technical details

Security Information

exposure of :5543

risk score

1/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp

every listening transport is another surface to filter at the edge

security overview

no security notes recorded for :5543 yet

known exploits, hardening advice, what a compromise looks like — suggest an edit if you know its exposure.

Record

iana registry entry

port: :5543
service: QF-Test License Server
transport: TCP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: IANA assigns TCP 5543 to the QF-Test License Server, a service associated with Quality First Software GmbH. The assignment alone does not establish the protocol details or typical deployment.
lookups: 0rank 993
added: 2026-10-08
updated: 2026-10-08
references: IANA service name registry — port 5543

Something wrong?

This record is maintained by the engineers who use port 5543. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-10-08.

01edit any field on a page of its own
02a model checks it for accuracy and spam
03clean and confident goes live immediately

edit this record →back to the registry

Related Ports

browse categories →

ports registered around :5543, by lookups.

port	service	proto	category	risk	views
:5555	Freeciv	TCP	Security	caution	26.9k
:5495	Applix TM1 Admin	TCP	Databases	caution	24.8k
:5500	VNC Viewer Listener	TCP	Remote Access	caution	15.1k
:5498	Hotline Tracker Server	TCP	File Transfer	caution	8.4k
:5550	HP Data Protector	TCP	File Transfer	caution	8.2k
:5517	Setiqueue Proxy	TCPtls	Cloud	caution	8.0k
:5501	Hotline File Transfer	TCP	File Transfer	caution	7.8k
:5591	Tidal Scheduler Master	TCP	System	caution	6.9k

risk mix of the 8 listed

caution100%

1 of 8 encrypted

Port :5543QF-Test License Server

Technical Details

Security Information

Related Ports

Port 5543QF-Test License Server