All ports

Port666/UDP

doom

Port

666

Protocol

UDP

Category

Well-Known

Service

doom

What is port 666?

Port 666/UDP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the doom service.

doom Id Software

Useful commands

nmapnmap -p 666 -sV example.com
netcatnc -zv example.com 666
curlcurl -v http://example.com:666/
telnettelnet example.com 666
bash(echo > /dev/udp/example.com/666) 2>/dev/null

Firewall commands

UFWAllow
sudo ufw allow 666/udp
Deny
sudo ufw deny 666/udp
iptablesAllow
sudo iptables -A INPUT -p udp --dport 666 -j ACCEPT
Deny
sudo iptables -D INPUT -p udp --dport 666 -j ACCEPT
firewalldAllow
sudo firewall-cmd --permanent --add-port=666/udp
WindowsAllow
netsh advfirewall firewall add rule name="Open Port 666" dir=in action=allow protocol=UDP localport=666

Security Risks

  • Unauthorized access to the service
  • Data exposure if the service is unauthenticated
  • Outdated versions with vulnerabilities
  • Incorrect service configuration

Frequently Asked Questions

What service runs on port 666/UDP?

Port 666/UDP is associated with the doom service. doom Id Software

Is it safe to expose port 666 to the Internet?

It depends on the service and configuration. Port 666 (doom) is a Well-Known port. If you need to expose it, keep the service updated, use strong authentication, and configure a firewall. It's always recommended to restrict access by IP when possible.

How do I check if port 666 is open?

You can use nmap: `nmap -p 666 -sV example.com`, netcat: `nc -zv example.com 666`, or the bash command: `(echo > /dev/udp/example.com/666) 2>/dev/null && echo "Open" || echo "Closed"`.

How do I open or close port 666 on my firewall?

On Linux with UFW: `sudo ufw allow 666/udp` (open) or `sudo ufw deny 666/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 666 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 666" dir=in action=allow protocol=UDP localport=666`.

What applications and services use port 666?

Port 666/UDP is used by the doom service. Specific uses depend on the software and configuration. Check our related tools section for more information.