• Wireshark (tshark)
• Tcpdump

• http://www.monitis.com/traceroute/

HTTP über Telnet:

• http://www.esqsoft.com/examples/troubleshooting-http-using-telnet.htm
• https://www.thomas-krenn.com/de/wiki/TCP_Port_80_(http)_Zugriff_mit_telnet_überprüfen

 echo -n "hello" >/dev/udp/localhost/8000

• http://stackoverflow.com/questions/9696129/how-to-send-only-one-udp-packet-with-netcat

• http://unix.stackexchange.com/questions/191655/using-bashs-dev-udp-how-would-i-know-if-the-port-was-open

https://www.cyberciti.biz/networking/nmap-command-examples-tutorials/

http://dnscheck.iis.se/?faq=1&test=standard

Falls SSH nicht funktioniert ist das meistens ein Problem falscher Permissions: http://www.openssh.com/faq.html

chmod 700 $HOME/.ssh
chmod go-w $HOME $HOME/.ssh
chmod 600 $HOME/.ssh/authorized_keys
chown `whoami` $HOME/.ssh/authorized_keys

 sudo netstat -lpn |grep :8080

• https://www.cyberciti.biz/faq/linux-unix-open-ports/