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// Other services

Port 12001: IBM Enterprise Extender SNA COS Network Priority

Port 12001 is assigned by IANA to entextnetwk (IBM Enterprise Extender SNA COS Network Priority).

12001

How entextnetwk works

Other services
client:12001entextnetwkresponse client:12001entextnetwkresponse

The client sends a request to port 12001 and the entextnetwk 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 12001 dangerous?

We have no specific security note for port 12001. 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 12001

ServicePortTransportDescriptionReferenceUpdated
entextnetwk 12001 TCP, UDP IBM Enterprise Extender SNA COS Network Priority - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 12001, and is it reachable?

Linux

sudo ss -ltnup 'sport = :12001'      # process listening on 12001
sudo lsof -nP -i :12001

macOS

sudo lsof -nP -i :12001

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 12001 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 12001
netstat -ano | findstr :12001

From another machine

nmap -p 12001 -sV <host>
sudo nmap -sU -p 12001 <host>
nc -zv <host> 12001

Block it in the firewall

sudo ufw deny 12001/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 12001" -Direction Inbound -LocalPort 12001 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 12001 used for?

Port 12001 is assigned by IANA to entextnetwk (IBM Enterprise Extender SNA COS Network Priority).

Is port 12001 TCP or UDP?

Port 12001 is registered for TCP and UDP.

Is it safe to open port 12001?

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 12001 is open?

On Linux run "ss -ltnup 'sport = :12001'", on macOS "lsof -nP -i :12001", and on Windows "netstat -ano | findstr :12001" to see the local process. From another machine, "nmap -p 12001 <host>" shows whether it is reachable.

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