All ports
Port21800/UDP
tvpmPort
21800
Protocol
UDP
Category
Registered
Service
tvpm
What is port 21800?
Port 21800/UDP is a Registered port, registered with IANA for specific applications. It is associated with the tvpm service.
TVNC Pro Multiplexing
Useful commands
nmapnmap -p 21800 -sV example.comnetcatnc -zv example.com 21800curlcurl -v http://example.com:21800/telnettelnet example.com 21800bash(echo > /dev/udp/example.com/21800) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 21800/udpDeny
sudo ufw deny 21800/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 21800 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 21800 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=21800/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 21800" dir=in action=allow protocol=UDP localport=21800Security 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- Outdated versions with vulnerabilities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 21800/UDP?
Port 21800/UDP is associated with the tvpm service. TVNC Pro Multiplexing
Is it safe to expose port 21800 to the Internet?
It depends on the service and configuration. Port 21800 (tvpm) 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 21800 is open?
You can use nmap: `nmap -p 21800 -sV example.com`, netcat: `nc -zv example.com 21800`, or the bash command: `(echo > /dev/udp/example.com/21800) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 21800 on my firewall?
On Linux with UFW: `sudo ufw allow 21800/udp` (open) or `sudo ufw deny 21800/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 21800 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 21800" dir=in action=allow protocol=UDP localport=21800`.
What applications and services use port 21800?
Port 21800/UDP is used by the tvpm service. Specific uses depend on the software and configuration. Check our related tools section for more information.