All ports
Port653/UDP
repscmdPort
653
Protocol
UDP
Category
Well-Known
Service
repscmd
What is port 653?
Port 653/UDP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the repscmd service.
RepCmd
Useful commands
nmapnmap -p 653 -sV example.comnetcatnc -zv example.com 653curlcurl -v http://example.com:653/telnettelnet example.com 653bash(echo > /dev/udp/example.com/653) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 653/udpDeny
sudo ufw deny 653/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 653 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 653 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=653/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 653" dir=in action=allow protocol=UDP localport=653Security 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- Outdated versions with vulnerabilities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 653/UDP?
Port 653/UDP is associated with the repscmd service. RepCmd
Is it safe to expose port 653 to the Internet?
It depends on the service and configuration. Port 653 (repscmd) 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 653 is open?
You can use nmap: `nmap -p 653 -sV example.com`, netcat: `nc -zv example.com 653`, or the bash command: `(echo > /dev/udp/example.com/653) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 653 on my firewall?
On Linux with UFW: `sudo ufw allow 653/udp` (open) or `sudo ufw deny 653/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 653 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 653" dir=in action=allow protocol=UDP localport=653`.
What applications and services use port 653?
Port 653/UDP is used by the repscmd service. Specific uses depend on the software and configuration. Check our related tools section for more information.