FWF-30E Packet Drops on LAN

[Solidence]

Good day ladies and gents,

Got a bit of a weird one here, I’m helping a Networks buddy to resolve an issue on a FortiWifi 30E and was hoping the community can give me some help.

About a month ago we started experiencing insanely slow internet speed, we did the normal troubleshooting and saw that when pinging the firewall on the internal IP we started getting random packet drops. We checked the Switch and LAN cable, no issue, all other local pings are just fine with 0 packet drops.
We backed up the unit and reset it too factory setting, but still exactly the same thing, any ideas on what it can be ?

[AEK]

Hello Solidence

You may check if there are packet errors or drops on your FortiGate related port and on the switch-port that is connected to FortiGate.

You can use the below command to check on FGT.

fnsysctl ifconfig

[Yurisk · Accepted solution]

Hi,

cannot share the solution, unfortunately, as couldn't find, but I've had few (2-3) FGT 30E units failing like that - all traffic PASSING through the firewall gets varying packet loss 3-7%, which is experienced as slow browsing, disconnections etc. But when pinging FGT interfaces - all looks perfect. Switched cables/ports, connected a PC directly to FGT instead of switch - all the same. Reset to factory defaults - no avail. The units were out of Support contract, so client just bought new ones and dropped these. 

[Solidence]

Thats exactly what we are experiancing. Pinging on the WAN's external IP of the firewall comes back with 0 packet drops, its only on the LAN IP address of the firewall that we see this happen.

This also causes massive issues when using internet sensitive kit like this client is.

[Yurisk]

Yep, as I mentioned my units were not covered by Support by that time already, otherwise I'd do TFTP firmware re-imaging, to be sure, and if this didn't help, would file RMA with the Fortinet.

[rtichkule]

Hello Solidence,

Please try connecting PC directly to the fortigate and initiate the ping.

Execute below command multiple times and check if the errors/dropped are increasing or not

#fnsysctl ifconfig <interface name>