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// Other services

Port 2543: REFTEK

Port 2543 is assigned by IANA to reftek (REFTEK).

2543

How reftek works

Other services
client:2543reftekresponse client:2543reftekresponse

The client sends a request to port 2543 and the reftek service answers.

Transport
TCP · UDP
Exposure risk
not rated depends on the program listening
Encryption
Unknownnot stated by the registry
IANA status
Assigned1 registered service
Range
Registered (1024-49151)
Category
Other services
01 Security

Is port 2543 dangerous?

We have no specific security note for port 2543. Its risk depends on the program actually listening on it. General advice for other services services:

  • Close the port if nothing on the host needs it.
  • Identify the process that listens on it (commands below) before opening it in a firewall.
  • Expose a service only to the networks that use it.
02 Registry

IANA registry entries for port 2543

ServicePortTransportDescriptionReferenceUpdated
reftek 2543 TCP, UDP REFTEK - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 2543, and is it reachable?

Linux

sudo ss -ltnup 'sport = :2543'      # process listening on 2543
sudo lsof -nP -i :2543

macOS

sudo lsof -nP -i :2543

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 2543 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 2543
netstat -ano | findstr :2543

From another machine

nmap -p 2543 -sV <host>
sudo nmap -sU -p 2543 <host>
nc -zv <host> 2543

Block it in the firewall

sudo ufw deny 2543/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 2543" -Direction Inbound -LocalPort 2543 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 2543 used for?

Port 2543 is assigned by IANA to reftek (REFTEK).

Is port 2543 TCP or UDP?

Port 2543 is registered for TCP and UDP.

Is it safe to open port 2543?

It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Close the port if nothing on the host needs it.

How do I check if port 2543 is open?

On Linux run "ss -ltnup 'sport = :2543'", on macOS "lsof -nP -i :2543", and on Windows "netstat -ano | findstr :2543" to see the local process. From another machine, "nmap -p 2543 <host>" shows whether it is reachable.

05 Related
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