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// Other services

Port 2397: NCL

Port 2397 is assigned by IANA to ncl (NCL).

2397

How ncl works

Other services
client:2397nclresponse client:2397nclresponse

The client sends a request to port 2397 and the ncl 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 2397 dangerous?

We have no specific security note for port 2397. 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 2397

ServicePortTransportDescriptionReferenceUpdated
ncl 2397 TCP, UDP NCL - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 2397, and is it reachable?

Linux

sudo ss -ltnup 'sport = :2397'      # process listening on 2397
sudo lsof -nP -i :2397

macOS

sudo lsof -nP -i :2397

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 2397 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 2397
netstat -ano | findstr :2397

From another machine

nmap -p 2397 -sV <host>
sudo nmap -sU -p 2397 <host>
nc -zv <host> 2397

Block it in the firewall

sudo ufw deny 2397/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 2397" -Direction Inbound -LocalPort 2397 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 2397 used for?

Port 2397 is assigned by IANA to ncl (NCL).

Is port 2397 TCP or UDP?

Port 2397 is registered for TCP and UDP.

Is it safe to open port 2397?

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 2397 is open?

On Linux run "ss -ltnup 'sport = :2397'", on macOS "lsof -nP -i :2397", and on Windows "netstat -ano | findstr :2397" to see the local process. From another machine, "nmap -p 2397 <host>" shows whether it is reachable.

05 Related
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