All ports
Port558/UDP
sdnskmpPort
558
Protocol
UDP
Category
Well-Known
Service
sdnskmp
What is port 558?
Port 558/UDP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the sdnskmp service.
SDNSKMP
Useful commands
nmapnmap -p 558 -sV example.comnetcatnc -zv example.com 558curlcurl -v http://example.com:558/telnettelnet example.com 558bash(echo > /dev/udp/example.com/558) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 558/udpDeny
sudo ufw deny 558/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 558 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 558 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=558/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 558" dir=in action=allow protocol=UDP localport=558Security Risks
- DNS cache poisoning attacks
- DDoS amplification using open DNS resolvers
- Information disclosure of internal subdomains
- Domain hijacking if DNS server is misconfigured
Frequently Asked Questions
What service runs on port 558/UDP?
Port 558/UDP is associated with the sdnskmp service. SDNSKMP
Is it safe to expose port 558 to the Internet?
It depends on the service and configuration. Port 558 (sdnskmp) is a Well-Known 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 558 is open?
You can use nmap: `nmap -p 558 -sV example.com`, netcat: `nc -zv example.com 558`, or the bash command: `(echo > /dev/udp/example.com/558) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 558 on my firewall?
On Linux with UFW: `sudo ufw allow 558/udp` (open) or `sudo ufw deny 558/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 558 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 558" dir=in action=allow protocol=UDP localport=558`.
What applications and services use port 558?
Port 558/UDP is used by the sdnskmp service. Specific uses depend on the software and configuration. Check our related tools section for more information.