All ports
Port3891/TCP
rtc-pm-portPort
3891
Protocol
TCP
Category
Registered
Service
rtc-pm-port
What is port 3891?
Port 3891/TCP is a Registered port, registered with IANA for specific applications. It is associated with the rtc-pm-port service.
Oracle RTC-PM port
Useful commands
nmapnmap -p 3891 -sV example.comnetcatnc -zv example.com 3891curlcurl -v http://example.com:3891/telnettelnet example.com 3891bash(echo > /dev/tcp/example.com/3891) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 3891/tcpDeny
sudo ufw deny 3891/tcpiptablesAllow
sudo iptables -A INPUT -p tcp --dport 3891 -j ACCEPTDeny
sudo iptables -D INPUT -p tcp --dport 3891 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=3891/tcpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 3891" dir=in action=allow protocol=TCP localport=3891Security 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- Outdated versions with vulnerabilities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 3891/TCP?
Port 3891/TCP is associated with the rtc-pm-port service. Oracle RTC-PM port
Is it safe to expose port 3891 to the Internet?
It depends on the service and configuration. Port 3891 (rtc-pm-port) is a Registered 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 3891 is open?
You can use nmap: `nmap -p 3891 -sV example.com`, netcat: `nc -zv example.com 3891`, or the bash command: `(echo > /dev/tcp/example.com/3891) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 3891 on my firewall?
On Linux with UFW: `sudo ufw allow 3891/tcp` (open) or `sudo ufw deny 3891/tcp` (close). With iptables: `sudo iptables -A INPUT -p tcp --dport 3891 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 3891" dir=in action=allow protocol=TCP localport=3891`.
What applications and services use port 3891?
Port 3891/TCP is used by the rtc-pm-port service. Specific uses depend on the software and configuration. Check our related tools section for more information.