SUDDEN NETWORK PACKET LOSS

[chrispng]

Hello dear Fortinet Community!

I am investigating a curious situation in a customers enviroment.

There is a continuous problem in 2 different VLANS (the first one is on an AP and the other on a wired VLAN)

The problem occurring is that the client PC suddenly drops packets.

I cant find anything unusual in the FGT error log history from the client IP both in the wireless VLAN or the wired one.

If the user hotspots from his mobile everything works fine.

The problem was first noticed in Video calls where the user would suddenly loose connectivity.

I tried pinging from the users pc , another pc on the same wired VLAN and from a different pc in the wireless one towards 8.8.8.8.

I can see packet losses but not at the same time and not a steady interval. It can happen from an hour to 10 minutes to two and half hours. Again i say it doesnt happens at all the different PCs at the same time.

To add the wired VLAN policy has only web flow based module, AV flow based module, DNS module and certificate inspection enabled

The problem is occuring at all the computers in the same floor (so same VLAN) for the wired one.

Is there anything i can look more from the fortigate side or should i focus on the internal Swiches ( FGT -> DELL CORE SWTCH -> FLOOR SWITCH)

Thanks in advance!

[adambomb1219]

Internal traffic?  External?  Only traffic through the FortiGate?  What is the switch?  What is the network topology?  What is the client?  How is the RF environment? How have we arrived at the conclusion the problem is the firewall? "I can see packet loss" - where? how? how much?

[AEK · Accepted solution]

Hi Chris

What I can suggest is to try isolate more the issue, and you are the one who can do this task. However here are some hints that may help:

• Try check FG and all switches on every port if the stats show dropped packets or TX/RX errors
• Try find the logic of the issue, like under which conditions it happens, is there a specific time slot, are the affected devices similar in some aspects, ...
• Check your traffic shaping policy (if any)

[chrispng]

Thanks both for the suggestions.

I will furthemore investigat and return with a more clear how IF its certainly the FGT.

Thanks in advance!