All ports
Port4321/TCP
rwhoisPort
4321
Protocol
TCP
Category
Registered
Service
rwhois
What is port 4321?
Port 4321/TCP is a Registered port, registered with IANA for specific applications. It is associated with the rwhois service.
Remote Who Is
Useful commands
nmapnmap -p 4321 -sV example.comnetcatnc -zv example.com 4321curlcurl -v http://example.com:4321/telnettelnet example.com 4321bash(echo > /dev/tcp/example.com/4321) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 4321/tcpDeny
sudo ufw deny 4321/tcpiptablesAllow
sudo iptables -A INPUT -p tcp --dport 4321 -j ACCEPTDeny
sudo iptables -D INPUT -p tcp --dport 4321 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=4321/tcpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 4321" dir=in action=allow protocol=TCP localport=4321Security 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- Outdated versions with vulnerabilities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 4321/TCP?
Port 4321/TCP is associated with the rwhois service. Remote Who Is
Is it safe to expose port 4321 to the Internet?
It depends on the service and configuration. Port 4321 (rwhois) 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 4321 is open?
You can use nmap: `nmap -p 4321 -sV example.com`, netcat: `nc -zv example.com 4321`, or the bash command: `(echo > /dev/tcp/example.com/4321) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 4321 on my firewall?
On Linux with UFW: `sudo ufw allow 4321/tcp` (open) or `sudo ufw deny 4321/tcp` (close). With iptables: `sudo iptables -A INPUT -p tcp --dport 4321 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 4321" dir=in action=allow protocol=TCP localport=4321`.
What applications and services use port 4321?
Port 4321/TCP is used by the rwhois service. Specific uses depend on the software and configuration. Check our related tools section for more information.