FORTIGATE FG200E CUTS INTERNET FROM 30MB/S TO 3MB/S

[wanumet]

Hello Team
I am new to this forum but have a big issue.
We have FG200E running on 

Firmware

v7.2.8 build1639 (Mature)

The ISP provides 30Mbps, and when we test with a laptop connected directly to the ODU, we get over 25Mbps; however, on Wi-Fi and LAN through the FortiGate, we get less than 5Mbps. 
There are not many configurations on the firewall, it is only working as a router and 1 site-to-site VPN which is not active.
Kindly guide me on how to solve this.

[nradia_FTNT]

Hello,

This is a useful KB article for troubleshooting bandwidth issues:

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Low-throughput-troubleshooting/ta-p/272657

[wanumet]

Hello @nradia_FTNT 

Thanks for the KB. After following it, I found nothing wrong with anything but still the Internet is slow. I really don't know what happened. 

[vbandha]

Hi @wanumet 

Can you try running a continuous ping from fortigate and end device to see if there is any packet loss?

https://community.fortinet.com/t5/FortiGate/Troubleshooting-Tip-Using-PING-options-from-the-FortiGat...

Can you also try using a different interface on fortigate if you get same speed there as well?

Also take a pcap on WAN interface and check if there is any retransmission or other errors seen there.

Regards,

Varun

[wanumet]

Hello @vbandha 

A continuous ping from an end device to the firewall does not break at all. Pinging the Google dns 8.8.8.8 also does not break. 

I will configure a new port and check