All ports
Port17/UDP
qotdPort
17
Protocol
UDP
Category
Well-Known
Service
qotd
What is port 17?
Port 17/UDP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the qotd service.
Quote of the Day
Useful commands
nmapnmap -p 17 -sV example.comnetcatnc -zv example.com 17curlcurl -v http://example.com:17/telnettelnet example.com 17bash(echo > /dev/udp/example.com/17) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 17/udpDeny
sudo ufw deny 17/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 17 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 17 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=17/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 17" dir=in action=allow protocol=UDP localport=17Security 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- Outdated versions with vulnerabilities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 17/UDP?
Port 17/UDP is associated with the qotd service. Quote of the Day
Is it safe to expose port 17 to the Internet?
It depends on the service and configuration. Port 17 (qotd) 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 17 is open?
You can use nmap: `nmap -p 17 -sV example.com`, netcat: `nc -zv example.com 17`, or the bash command: `(echo > /dev/udp/example.com/17) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 17 on my firewall?
On Linux with UFW: `sudo ufw allow 17/udp` (open) or `sudo ufw deny 17/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 17 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 17" dir=in action=allow protocol=UDP localport=17`.
What applications and services use port 17?
Port 17/UDP is used by the qotd service. Specific uses depend on the software and configuration. Check our related tools section for more information.