All ports
Port22/UDP
sshPort
22
Protocol
UDP
Category
Well-Known
Service
ssh
What is port 22?
Port 22/UDP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the ssh service.
The Secure Shell (SSH) Protocol
Useful commands
nmapnmap -p 22 -sV example.comnetcatnc -zv example.com 22curlcurl -v http://example.com:22/telnettelnet example.com 22bash(echo > /dev/udp/example.com/22) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 22/udpDeny
sudo ufw deny 22/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 22 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 22 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=22/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 22" dir=in action=allow protocol=UDP localport=22Security Risks
- Unauthorized remote access to the server
- Brute force attacks against SSH credentials
- Exposure of private keys or misconfigurations
- Outdated versions with known vulnerabilities
Frequently Asked Questions
What service runs on port 22/UDP?
Port 22/UDP is associated with the ssh service. The Secure Shell (SSH) Protocol
Is it safe to expose port 22 to the Internet?
It depends on the service and configuration. Port 22 (ssh) 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 22 is open?
You can use nmap: `nmap -p 22 -sV example.com`, netcat: `nc -zv example.com 22`, or the bash command: `(echo > /dev/udp/example.com/22) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 22 on my firewall?
On Linux with UFW: `sudo ufw allow 22/udp` (open) or `sudo ufw deny 22/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 22 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 22" dir=in action=allow protocol=UDP localport=22`.
What applications and services use port 22?
Port 22/UDP is used by the ssh service. Specific uses depend on the software and configuration. Check our related tools section for more information.