CyberHunter
Local dataset, no network
// Other services

Port 2540: LonWorks

Port 2540 is assigned by IANA to lonworks (LonWorks).

2540

How lonworks works

Other services
client:2540lonworksresponse client:2540lonworksresponse

The client sends a request to port 2540 and the lonworks 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 2540 dangerous?

We have no specific security note for port 2540. 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 2540

ServicePortTransportDescriptionReferenceUpdated
lonworks 2540 TCP, UDP LonWorks - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 2540, and is it reachable?

Linux

sudo ss -ltnup 'sport = :2540'      # process listening on 2540
sudo lsof -nP -i :2540

macOS

sudo lsof -nP -i :2540

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 2540 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 2540
netstat -ano | findstr :2540

From another machine

nmap -p 2540 -sV <host>
sudo nmap -sU -p 2540 <host>
nc -zv <host> 2540

Block it in the firewall

sudo ufw deny 2540/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 2540" -Direction Inbound -LocalPort 2540 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 2540 used for?

Port 2540 is assigned by IANA to lonworks (LonWorks).

Is port 2540 TCP or UDP?

Port 2540 is registered for TCP and UDP.

Is it safe to open port 2540?

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 2540 is open?

On Linux run "ss -ltnup 'sport = :2540'", on macOS "lsof -nP -i :2540", and on Windows "netstat -ano | findstr :2540" to see the local process. From another machine, "nmap -p 2540 <host>" shows whether it is reachable.

05 Related

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