Troubleshooting Tip: How to identify interface is defective

[samandeep]

Description	This article describes how to troubleshoot and identify that the interface/port is defective.
Scope	FortiGate: All models.
Solution	Troubleshooting Steps:  Check the Physical Port Link Light. If lit, proceed to Step 2. If not, proceed to Step 4.  Check FortiGate GUI. Verify if the interface status is set to enable in the GUI.  Check Sniffer on FortiGate CLI. Run the command: diag sniffer packet <interface> " " 4 0 l. Swap the Device to a Different Port. Unplug the device and plug it into a different FortiGate port.  If the device connects successfully, the original interface might be defective. Check Interface Status. Run the command: diag hardware deviceinfo nic <interface>. For example: krypton-kvm09 # diagnose hardware deviceinfo nic port4 Name: port4 Driver: virtio_net Version: 1.0.0 Bus: 0000:00:09.0 HWaddr: 00:6b:72:79:09:04 Permanent Hwaddr:00:6b:72:79:09:04 State: down Link: down Mtu: 1500 Supported: Advertised: Auto: disabled RX Ring: 256 TX Ring: 256 Rx packets: 2508 Rx bytes: 575464 Rx compressed: 0 Rx dropped: 0 Rx errors: 0 Rx Length err: 0 Rx Buf overflow: 0 Rx Crc err: 0 Rx Frame err: 0 Rx Fifo overrun: 0 Rx Missed packets: 0 Tx packets: 110270 Tx bytes: 4631862 Tx compressed: 0 Tx dropped: 0 Tx errors: 0 Tx Aborted err: 0 Tx Carrier err: 0 Tx Fifo overrun: 0 Tx Heartbeat err: 0 Tx Window err: 0 Multicasts: 0 Collisions: 0 Document Referred: Troubleshooting Tip: FortiGate interface error counters. Format the Device and Reload the Firmware. Prepare to format the device and reload the firmware to see if it resolves the issue. Document Referred: Technical Tip: Formatting and loading FortiGate firmware image using TFTP. Run HQIP Test. If the interface still does not respond, run the HQIP test, open a ticket with TAC, and provide all the above outputs and HQIP test results.  Document referred: Technical Tip: RMA - HQIP test (with built-in FortiOS diagnostic commands)  By following the above steps, the issue can be isolated to either the interface or the device itself.