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// Other services

Port 5681: Net-coneX Control Protocol

Port 5681 is assigned by IANA to ncxcp (Net-coneX Control Protocol).

5681

How ncxcp works

Other services
client:5681ncxcpresponse client:5681ncxcpresponse

The client sends a request to port 5681 and the ncxcp 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 5681 dangerous?

We have no specific security note for port 5681. 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 5681

ServicePortTransportDescriptionReferenceUpdated
ncxcp 5681 TCP, UDP Net-coneX Control Protocol - 2006-06

// source: IANA service name and port number registry

03 Check it

Which program uses port 5681, and is it reachable?

Linux

sudo ss -ltnup 'sport = :5681'      # process listening on 5681
sudo lsof -nP -i :5681

macOS

sudo lsof -nP -i :5681

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 5681 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 5681
netstat -ano | findstr :5681

From another machine

nmap -p 5681 -sV <host>
sudo nmap -sU -p 5681 <host>
nc -zv <host> 5681

Block it in the firewall

sudo ufw deny 5681/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 5681" -Direction Inbound -LocalPort 5681 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 5681 used for?

Port 5681 is assigned by IANA to ncxcp (Net-coneX Control Protocol).

Is port 5681 TCP or UDP?

Port 5681 is registered for TCP and UDP.

Is it safe to open port 5681?

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 5681 is open?

On Linux run "ss -ltnup 'sport = :5681'", on macOS "lsof -nP -i :5681", and on Windows "netstat -ano | findstr :5681" to see the local process. From another machine, "nmap -p 5681 <host>" shows whether it is reachable.

05 Related
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