Extremely slooooow LAN-to-LAN IPSec download
Router A <== internet ==> Router B, internet speed 100Mbps
Router A: ER605 v2 , Vigor2926 (for troubleshooting)
Router B: Fortigate v7.2
A NAS is connected to Site B,
Both routers are direct connect to internet, no NAT
IPsec tunnel is successfully connected, both side can ping each other subnet
upload file from A => B, good speed, ~10MB/s
download file from B, extremely sloooooow, ~0.2MB/s, and always stop download over a few seconds
Download means SMB, https, etc from the NAS
Tested TWO ER605 v2, exactly same result.
Replace ER605 v2 with a very old Vigor2926, both upload and download speed normal, reach ~10MB/s, so, no issue with site B configuration.