CyberHunter
// Other services

Port 3743: IP Control Systems Ltd.

Port 3743 is assigned by IANA to ipcs-command (IP Control Systems Ltd.).

3743

How ipcs-command works

Other services
client:3743ipcs-commandresponse client:3743ipcs-commandresponse

The client sends a request to port 3743 and the ipcs-command 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)
01 Security

Is port 3743 dangerous?

We have no specific security note for port 3743. 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 3743

ServicePortTransportDescriptionReferenceUpdated
ipcs-command 3743 TCP, UDP IP Control Systems Ltd. - 2003-04

// source: IANA service name and port number registry

03 Check it

Which program uses port 3743, and is it reachable?

Linux

sudo ss -ltnup 'sport = :3743'      # process listening on 3743
sudo lsof -nP -i :3743

macOS

sudo lsof -nP -i :3743

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 3743 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 3743
netstat -ano | findstr :3743

From another machine

nmap -p 3743 -sV <host>
sudo nmap -sU -p 3743 <host>
nc -zv <host> 3743

Block it in the firewall

sudo ufw deny 3743/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 3743" -Direction Inbound -LocalPort 3743 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 3743 used for?

Port 3743 is assigned by IANA to ipcs-command (IP Control Systems Ltd.).

Is port 3743 TCP or UDP?

Port 3743 is registered for TCP and UDP.

Is it safe to open port 3743?

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 3743 is open?

On Linux run "ss -ltnup 'sport = :3743'", on macOS "lsof -nP -i :3743", and on Windows "netstat -ano | findstr :3743" to see the local process. From another machine, "nmap -p 3743 <host>" shows whether it is reachable.

05 Related