CyberHunter
Local dataset, no network
// Other services

Port 3818: Crinis Heartbeat

Port 3818 is assigned by IANA to crinis-hb (Crinis Heartbeat).

3818

How crinis-hb works

Other services
client:3818crinis-hbresponse client:3818crinis-hbresponse

The client sends a request to port 3818 and the crinis-hb 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 3818 dangerous?

We have no specific security note for port 3818. 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 3818

ServicePortTransportDescriptionReferenceUpdated
crinis-hb 3818 TCP, UDP Crinis Heartbeat - 2004-04

// source: IANA service name and port number registry

03 Check it

Which program uses port 3818, and is it reachable?

Linux

sudo ss -ltnup 'sport = :3818'      # process listening on 3818
sudo lsof -nP -i :3818

macOS

sudo lsof -nP -i :3818

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 3818 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 3818
netstat -ano | findstr :3818

From another machine

nmap -p 3818 -sV <host>
sudo nmap -sU -p 3818 <host>
nc -zv <host> 3818

Block it in the firewall

sudo ufw deny 3818/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 3818" -Direction Inbound -LocalPort 3818 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 3818 used for?

Port 3818 is assigned by IANA to crinis-hb (Crinis Heartbeat).

Is port 3818 TCP or UDP?

Port 3818 is registered for TCP and UDP.

Is it safe to open port 3818?

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 3818 is open?

On Linux run "ss -ltnup 'sport = :3818'", on macOS "lsof -nP -i :3818", and on Windows "netstat -ano | findstr :3818" to see the local process. From another machine, "nmap -p 3818 <host>" shows whether it is reachable.

05 Related
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