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// Other services

Port 6321: Empress Software Connectivity Server 1

Port 6321 is assigned by IANA to emp-server1 (Empress Software Connectivity Server 1).

6321

How emp-server1 works

Other services
client:6321emp-server1response client:6321emp-server1response

The client sends a request to port 6321 and the emp-server1 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 6321 dangerous?

We have no specific security note for port 6321. 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 6321

ServicePortTransportDescriptionReferenceUpdated
emp-server1 6321 TCP, UDP Empress Software Connectivity Server 1 - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 6321, and is it reachable?

Linux

sudo ss -ltnup 'sport = :6321'      # process listening on 6321
sudo lsof -nP -i :6321

macOS

sudo lsof -nP -i :6321

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 6321 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 6321
netstat -ano | findstr :6321

From another machine

nmap -p 6321 -sV <host>
sudo nmap -sU -p 6321 <host>
nc -zv <host> 6321

Block it in the firewall

sudo ufw deny 6321/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 6321" -Direction Inbound -LocalPort 6321 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 6321 used for?

Port 6321 is assigned by IANA to emp-server1 (Empress Software Connectivity Server 1).

Is port 6321 TCP or UDP?

Port 6321 is registered for TCP and UDP.

Is it safe to open port 6321?

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 6321 is open?

On Linux run "ss -ltnup 'sport = :6321'", on macOS "lsof -nP -i :6321", and on Windows "netstat -ano | findstr :6321" to see the local process. From another machine, "nmap -p 6321 <host>" shows whether it is reachable.

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