CyberHunter
// Network services

Port 18242: Checkpoint router monitoring

Port 18242 is assigned by IANA to iclid (Checkpoint router monitoring).

18242

How iclid works

Network services
client:18242iclidresponse client:18242iclidresponse

The client sends a request to port 18242 and the iclid service answers.

Transport
TCP
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 18242 dangerous?

We have no specific security note for port 18242. Its risk depends on the program actually listening on it. General advice for network services services:

  • Answer only the networks that need the service (no open resolvers, relays or reflectors).
  • UDP services can be abused for DDoS amplification: rate-limit or block them at the edge.
  • Disable legacy test services that have no use in production.
02 Registry

IANA registry entries for port 18242

ServicePortTransportDescriptionReferenceUpdated
iclid 18242 TCP Checkpoint router monitoring - 2012-06-28
-18242-Reserved--

// source: IANA service name and port number registry

03 Check it

Which program uses port 18242, and is it reachable?

Linux

sudo ss -ltnup 'sport = :18242'      # process listening on 18242
sudo lsof -nP -i :18242

macOS

sudo lsof -nP -i :18242

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 18242 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 18242
netstat -ano | findstr :18242

From another machine

nmap -p 18242 -sV <host>
nc -zv <host> 18242

Block it in the firewall

sudo ufw deny 18242/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 18242" -Direction Inbound -LocalPort 18242 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 18242 used for?

Port 18242 is assigned by IANA to iclid (Checkpoint router monitoring).

Is port 18242 TCP or UDP?

Port 18242 is registered for TCP.

Is it safe to open port 18242?

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. Answer only the networks that need the service (no open resolvers, relays or reflectors).

How do I check if port 18242 is open?

On Linux run "ss -ltnup 'sport = :18242'", on macOS "lsof -nP -i :18242", and on Windows "netstat -ano | findstr :18242" to see the local process. From another machine, "nmap -p 18242 <host>" shows whether it is reachable.

05 Related