Troubleshooting routing
The tools that we will see in the following paragraphs will be required to troubleshoot the addressing and routing features of the TCP/IP protocol. Before we proceed to explain the single tools and commands for troubleshooting, we can take advantage of a real-world suggestion. In order to perform the troubleshooting steps in a more comfortable way, it is often advisable to use a client for SSH and Telnet such as PuTTY (http://bit.ly/1kyS98), to launch two separate sessions on a FortiGate unit. One of the two consoles will be dedicated to watch the results of the debug commands. The second console will be dedicated to launch commands, such as ping and traceroute that we will use to trigger actions that will be visible in the first open console. In the following screenshot we have a diagnose sniffer packet port1 icmp command running on the session opened to the left-hand side and an execute ping command on the session opened on the right-hand side window:
