This article describes how to use the built-in packet capture feature in FortiOS from the GUI interface.
On the 5.6 firmware branch, the unit needs a disk and logging to disk has to be enabled.
Since the firmware version 6.0.2, this restriction has been removed.
Here is the Step-by-Step guide to capturing packets from GUI:
The option to capture the packet based on interface and filter by hosts, ports or VLANs will be proposed.
In the example above 100 packets would be captured based on the selected filters:
IP address 10.205.1.206 and port 80,443 on interface port 3.
If 'Enable Filters' is not selected, all packets on the selected interface will be captured.
Packet capture can tell what is happening on the network at a low level. This can be very useful for troubleshooting problems, such as:
On FortiGate Version 7.2+ this option can be found under Network -> Diagnostics.