Ipsec tunnel to Azure

[chiner]

Hello,

we have created a ipsec tunnel to a azure machine and we found out that we have a very poor performance. When we want to copy some files from our fileserver to the virtual machine on Azure we can copy a 1 GB file in ca. 30min. Do you have any suggestion how to troubleshoot this problem? Or maybe are there some settings on the fortigate site (MTU, etc.).

We are using the VpnGw1 Gateway Throughput 650Mbps.

Thank you for your help.

[gfleming]

There are many variables that can play into poor performance. Do you have a baseline metric showing the throughput is as advertised on a non-VPN connection?

What's the latency between the Azure machine and the on prem machine?

Can you run an iperf or other speed test over the raw link to see how it performs?

[sjoshi]

Dear chiner,

Thank you for posting to the Fortinet Community Forum.

Problem Description:-

Ipsec tunnel to Azure

You are facing issue with slow file transfer through IPSEC TNL.

You can check by reducing the mss value.

Please follow the link below

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Setting-TCP-MSS-value/ta-p/194518

Also you can perform the ipref test.

Please follow the link below

https://community.fortinet.com/t5/FortiGate/Troubleshooting-Tip-How-to-troubleshoot-speed-or-bandwid...

Let us know if this helps.

Thanks