Issue with slow Internet on LAN side thus its fast per speedtest from OPNsense

[jmboettger]

I have a fresh install of
OPNsense 19.7.5-amd64, FreeBSD 11.2-RELEASE-p14-HBSD, OpenSSL 1.0.2t 10 Sep 2019 on a Atom C3558 @8GB RAM, 120 GB SSD and 4 Intel 10GbE NIC (ix).

On WAN side i have 600 Mbit / 60 Mbit, which i could verify on the System via speedtest-cli.
On LAN side (Windows 10) i get no more than 80Mbit/60Mbit thus a iperf from LAN side to the OPNSense comes with 876Mbit.

• Antivirus is switched off
• hardware checksum offloading is dissabled
• I do have no shaper, QOS, IDS active / installed
• I added kern.ipc.nmbclusters="1000000", kern.ipc.nmbjumbop="524288" to /boot/loader.conf.local
• as well as hw.intr_storm_threshold=10000 to the tunables
• I added dev.ix.0.fc=0 for every nic on board (dev.ix.1.fc=0, dev.ix.2.fc=0 etc).
• I changed every cable.

None of the mentioned measures changed something.
CPU load is no more than 0.32 at maximum and there are no collisions or or errors shown on the interface.
I even changed the MSS on lan side to 1400.
No change at all. Does anybody has an idea what the reason could be?
Best regards and thanks in advance.