Troubleshooting

• Wireshark (tshark)
• Tcpdump Tutorial 1
• Tcpdump Tutorial 2

• http://whatismyip.ch

• https://dnslytics.com/tools
• https://dnslytics.com/ip/141.45.184.41

Visual Traceroute

• http://www.monitis.com/traceroute/

Traceroute mit Anzeige des Autonomen Systems (AS)

traceroute -a www.spiegel.de

HTTP über Telnet:

telnet www.spiegel.de 80
 
GET / HTTP/1.1
host: www.spiegel.de

• 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

HTTP über openssl:

• http://www.h-online.com/security/features/Testing-email-with-encryption-812464.html

SMTP über Telnet:

• https://www.thomas-krenn.com/de/wiki/TCP_Port_25_(smtp)_Zugriff_mit_telnet_überprüfen

SMTP über SSL:

• http://www.h-online.com/security/features/Testing-email-with-encryption-812464.html

 echo -n "hello" >/dev/udp/localhost/8000 #may prefer IPv6!
 echo -n "hello" >/dev/udp/127.0.0.1/8000

• https://help.ubidots.com/developer-guides/sending-tcpudp-packets-using-netcat
• 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

 netstat -vanp tcp | grep 443
 lsof -i tcp:443
 # anschließend mit ps das Programm ermitteln
 ps -p PID

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

Mac

 ctrl + ü

Windows

 ctrl + +

• http://superuser.com/questions/398/how-to-send-the-escape-character-on-os-x-terminal