Slow throughput once again, speedtest-cli

Hey friends, how are you doing?

Today i have built up a new OpenWrt machine, using an 1 HE Supermicro Server with Xeon 1230v2 CPU, and 8GB of memory.
Furthermore i have connected the device to the network using 2 links as LACP LAG to my Cisco switch.
Now there is an issue. I've got a 1Gbps internet connection, and unfortunately i only get around 500mbps when running a speedtest on my OpenWrt device.
When i connect to the ISP VLAN directly i get the full 1Gbps. So somehow the OpenWrt device is limiting.
QoS or SQM are not enabled. But i am running mwan3.
Also the CPU load is at around 7% during downloads.

What is the best-practice way in order to troubleshoot this issue?

iperf3 on Gigabit LAN to the OpenWrt device.

Accepted connection from fdfb:9584:eb33:3:7aeb:71eb:bcd7:256b, port 57970
[  5] local fdfb:9584:eb33:3::1 port 5201 connected to fdfb:9584:eb33:3:7aeb:71eb:bcd7:256b port 57972
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec   110 MBytes   919 Mbits/sec                  
[  5]   1.00-2.00   sec   103 MBytes   861 Mbits/sec                  
[  5]   2.00-3.00   sec  93.9 MBytes   787 Mbits/sec                  
[  5]   3.00-4.00   sec   103 MBytes   864 Mbits/sec                  
[  5]   4.00-5.00   sec  93.9 MBytes   787 Mbits/sec                  
[  5]   5.00-6.00   sec   108 MBytes   906 Mbits/sec                  
[  5]   6.00-7.00   sec   110 MBytes   922 Mbits/sec                  
[  5]   7.00-8.00   sec   108 MBytes   904 Mbits/sec                  
[  5]   8.00-9.00   sec   110 MBytes   923 Mbits/sec                  
[  5]   9.00-10.00  sec   107 MBytes   898 Mbits/sec                  
[  5]  10.00-10.00  sec   141 KBytes   792 Mbits/sec                  

Thanks in advance!

root@OpenWrt:/tmp# speedtest-ookla 

   Speedtest by Ookla

     Server: myLoc managed IT AG - Dusseldorf (id = 17392)
        ISP: Vodafone Germany
    Latency:     7.27 ms   (3.32 ms jitter)
   Download:   544.40 Mbps (data used: 1.0 GB)                               
     Upload:    50.43 Mbps (data used: 25.3 MB)                               
Packet Loss:     0.0%
 Result URL:

Run the following and post the results...

ubus call system board; \
uci export network; uci export wireless; \
uci export dhcp; uci export firewall; \
head -n -0 /etc/firewall.user; \
ip -4 addr ; ip -4 ro li tab all ; ip -4 ru; \
ip -6 addr ; ip -6 ro li tab all ; ip -6 ru; \
ls -l  /etc/resolv.* /tmp/resolv.* /tmp/resolv.*/* ; head -n -0 /etc/resolv.* /tmp/resolv.* /tmp/resolv.*/*

Note: Redact any passwords, MAC addresses, and your public IP.

Alright, thanks! Here you go.
I have exceeded the allowed amount of characters. So its on pastebin now.

Haven't dug in too deeply, but is there some reason the MTU is set to 1420 and not 1500 in these 2 places?

17: Hub: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1420 qdisc noqueue state UNKNOWN group default qlen 1000
inet brd scope global Hub

17: Hub: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1420 state UNKNOWN qlen 1000
inet6 XXXX:XXX:230:5285::1/64 scope global dynamic noprefixroute
valid_lft 5419sec preferred_lft 1819sec

1 Like

Hey friend, thanks for your help!
I am sorry for my late reply, but there was an issue in my switched network infrastructure, so i didn't want to make any guesses before.
The issue wasn't caused by the OpenWrt device itself, but by a bad switch, producing packets with FCS errors. I have replaced it by one of my old Catalyst 2960G switches and now everything is running as expected!
Thanks a lot for your help though!