All ports
Port84/UDP
ctfPort
84
Protocol
UDP
Category
Well-Known
Service
ctf
What is port 84?
Port 84/UDP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the ctf service.
Common Trace Facility
Useful commands
nmapnmap -p 84 -sV example.comnetcatnc -zv example.com 84curlcurl -v http://example.com:84/telnettelnet example.com 84bash(echo > /dev/udp/example.com/84) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 84/udpDeny
sudo ufw deny 84/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 84 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 84 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=84/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 84" dir=in action=allow protocol=UDP localport=84Security 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- Outdated versions with vulnerabilities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 84/UDP?
Port 84/UDP is associated with the ctf service. Common Trace Facility
Is it safe to expose port 84 to the Internet?
It depends on the service and configuration. Port 84 (ctf) 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 84 is open?
You can use nmap: `nmap -p 84 -sV example.com`, netcat: `nc -zv example.com 84`, or the bash command: `(echo > /dev/udp/example.com/84) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 84 on my firewall?
On Linux with UFW: `sudo ufw allow 84/udp` (open) or `sudo ufw deny 84/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 84 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 84" dir=in action=allow protocol=UDP localport=84`.
What applications and services use port 84?
Port 84/UDP is used by the ctf service. Specific uses depend on the software and configuration. Check our related tools section for more information.