All ports
Port6623/UDP
ktelnetPort
6623
Protocol
UDP
Category
Registered
Service
ktelnet
What is port 6623?
Port 6623/UDP is a Registered port, registered with IANA for specific applications. It is associated with the ktelnet service.
Kerberos V5 Telnet
Useful commands
nmapnmap -p 6623 -sV example.comnetcatnc -zv example.com 6623curlcurl -v http://example.com:6623/telnettelnet example.com 6623bash(echo > /dev/udp/example.com/6623) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 6623/udpDeny
sudo ufw deny 6623/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 6623 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 6623 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=6623/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 6623" dir=in action=allow protocol=UDP localport=6623Security 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- Outdated versions with vulnerabilities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 6623/UDP?
Port 6623/UDP is associated with the ktelnet service. Kerberos V5 Telnet
Is it safe to expose port 6623 to the Internet?
It depends on the service and configuration. Port 6623 (ktelnet) 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 6623 is open?
You can use nmap: `nmap -p 6623 -sV example.com`, netcat: `nc -zv example.com 6623`, or the bash command: `(echo > /dev/udp/example.com/6623) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 6623 on my firewall?
On Linux with UFW: `sudo ufw allow 6623/udp` (open) or `sudo ufw deny 6623/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 6623 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 6623" dir=in action=allow protocol=UDP localport=6623`.
What applications and services use port 6623?
Port 6623/UDP is used by the ktelnet service. Specific uses depend on the software and configuration. Check our related tools section for more information.