All ports
Port309/UDP
entrusttimePort
309
Protocol
UDP
Category
Well-Known
Service
entrusttime
What is port 309?
Port 309/UDP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the entrusttime service.
EntrustTime
Useful commands
nmapnmap -p 309 -sV example.comnetcatnc -zv example.com 309curlcurl -v http://example.com:309/telnettelnet example.com 309bash(echo > /dev/udp/example.com/309) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 309/udpDeny
sudo ufw deny 309/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 309 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 309 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=309/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 309" dir=in action=allow protocol=UDP localport=309Security 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- Outdated versions with vulnerabilities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 309/UDP?
Port 309/UDP is associated with the entrusttime service. EntrustTime
Is it safe to expose port 309 to the Internet?
It depends on the service and configuration. Port 309 (entrusttime) 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 309 is open?
You can use nmap: `nmap -p 309 -sV example.com`, netcat: `nc -zv example.com 309`, or the bash command: `(echo > /dev/udp/example.com/309) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 309 on my firewall?
On Linux with UFW: `sudo ufw allow 309/udp` (open) or `sudo ufw deny 309/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 309 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 309" dir=in action=allow protocol=UDP localport=309`.
What applications and services use port 309?
Port 309/UDP is used by the entrusttime service. Specific uses depend on the software and configuration. Check our related tools section for more information.