All ports
Port21847/UDP
netspeak-csPort
21847
Protocol
UDP
Category
Registered
Service
netspeak-cs
What is port 21847?
Port 21847/UDP is a Registered port, registered with IANA for specific applications. It is associated with the netspeak-cs service.
NetSpeak Corp. Connection Services
Useful commands
nmapnmap -p 21847 -sV example.comnetcatnc -zv example.com 21847curlcurl -v http://example.com:21847/telnettelnet example.com 21847bash(echo > /dev/udp/example.com/21847) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 21847/udpDeny
sudo ufw deny 21847/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 21847 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 21847 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=21847/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 21847" dir=in action=allow protocol=UDP localport=21847Security 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- Outdated versions with vulnerabilities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 21847/UDP?
Port 21847/UDP is associated with the netspeak-cs service. NetSpeak Corp. Connection Services
Is it safe to expose port 21847 to the Internet?
It depends on the service and configuration. Port 21847 (netspeak-cs) 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 21847 is open?
You can use nmap: `nmap -p 21847 -sV example.com`, netcat: `nc -zv example.com 21847`, or the bash command: `(echo > /dev/udp/example.com/21847) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 21847 on my firewall?
On Linux with UFW: `sudo ufw allow 21847/udp` (open) or `sudo ufw deny 21847/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 21847 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 21847" dir=in action=allow protocol=UDP localport=21847`.
What applications and services use port 21847?
Port 21847/UDP is used by the netspeak-cs service. Specific uses depend on the software and configuration. Check our related tools section for more information.