Slow ethernet iperf3 speeds until reboot

What’s the network setup like?

Directly wired to the router.
The weird thing is, before restarting the device my router was displaying 1 Gbit/s connection. Now it display 100 Mbit/s.

Can you try a different cable?

Sure. Give me a moment.

Would have been my next question. I am using Cat6 RJ45 cables here. Makes life easier :wink:

Sam - yes the speeds go back to 938mb after this. (it crashed the box the first time)

thats not what happens to me - everything stays at 1GB but the vero slows down to about 150-200mb speed.

I have a very small no of dropped packets:
ifconfig
eth0: flags=-28605<UP,BROADCAST,RUNNING,MULTICAST,DYNAMIC> mtu 1500
inet 192.168.1.24 netmask 255.255.255.0 broadcast 192.168.1.255
ether c4:4e:ac:28:5d:20 txqueuelen 1000 (Ethernet)
RX packets 1868700 bytes 2715279385 (2.5 GiB)
RX errors 0 dropped 10 overruns 0 frame 0
TX packets 90601 bytes 20017780 (19.0 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 40

Switched cable and restarted device 3 mins ago.
Result of ifconfig:

eth0: flags=-28605<UP,BROADCAST,RUNNING,MULTICAST,DYNAMIC>  mtu 1500
    inet 192.168.178.25  netmask 255.255.255.0  broadcast 192.168.178.255
    ether 90:0e:b3:01:c7:31  txqueuelen 1000  (Ethernet)
    RX packets 733  bytes 59552 (58.1 KiB)
    RX errors 0  dropped 440  overruns 0  frame 0
    TX packets 328  bytes 41466 (40.4 KiB)
    TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    device interrupt 40

you seem to have an awful lot of dropped packets compared with the total. You have a connection problem somewhere, or a dodgy bit of hardware.

Doing ifconfig on my Pi which is used solely for pihole doesn’t show any dropped packets

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
    inet 192.168.178.32  netmask 255.255.255.0  broadcast 192.168.178.255
    inet6 fe80::7bb1:441a:181e:9f8f  prefixlen 64  scopeid 0x20<link>
    inet6 2001:4dd4:1730:0:c4ba:e19:34ea:ce8b  prefixlen 64  scopeid 0x0<global>
    ether b8:27:eb:1b:56:27  txqueuelen 1000  (Ethernet)
    RX packets 1207672  bytes 64175186 (61.2 MiB)
    RX errors 0  dropped 0  overruns 0  frame 0
    TX packets 92551  bytes 17830118 (17.0 MiB)
    TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Is that connected with the same cable, port on router etc?

No. Setup is:
Router (Port 1) -> 10m cable -> Vero
Router (Port 3) -> 15cm cable -> Pi

But I can test it on the same port with the same cable.

Just connected the Pi with the same cable and port as the Vero -> no drops.

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
    inet 192.168.178.32  netmask 255.255.255.0  broadcast 192.168.178.255
    inet6 2001:4dd4:1730:0:c4ba:e19:34ea:ce8b  prefixlen 64  scopeid 0x0<global>
    inet6 fe80::7bb1:441a:181e:9f8f  prefixlen 64  scopeid 0x20<link>
    ether b8:27:eb:1b:56:27  txqueuelen 1000  (Ethernet)
    RX packets 1142  bytes 137019 (133.8 KiB)
    RX errors 0  dropped 0  overruns 0  frame 0
    TX packets 1484  bytes 1300551 (1.2 MiB)
    TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Okay that’s weird. I just installed OSMC on my Pi on another SD card and now the Pi is also showing drops:

eth0: flags=-28605<UP,BROADCAST,RUNNING,MULTICAST,DYNAMIC>  mtu 1500
    inet 192.168.178.32  netmask 255.255.255.0  broadcast 192.168.178.255
    ether b8:27:eb:1b:56:27  txqueuelen 1000  (Ethernet)
    RX packets 372  bytes 27774 (27.1 KiB)
    RX errors 0  dropped 160  overruns 0  frame 0
    TX packets 211  bytes 30289 (29.5 KiB)
    TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

After switching back to the SD card with the Pihole installation, everything is fine again.
So it seems like I only get those drops when running OSMC on either the Pi or the Vero.

My speed has just dropped off within the day again, getting more and more frequent. My ifconfig still shows v low dropped packets:
ifconfig
eth0: flags=-28605<UP,BROADCAST,RUNNING,MULTICAST,DYNAMIC> mtu 1500
inet 192.168.1.24 netmask 255.255.255.0 broadcast 192.168.1.255
ether c4:4e:ac:28:5d:20 txqueuelen 1000 (Ethernet)
RX packets 2875247 bytes 4256775632 (3.9 GiB)
RX errors 0 dropped 10 overruns 0 frame 0
TX packets 219141 bytes 175813896 (167.6 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 40

Did you try as I suggested and disable iptv.merge? It was filling your logs and may be using up network resources.

Thats the next step, yes.

Guys - some dropped packets when you restart a device are normal, especially if you were logged in and the ssh client still tries to connect. When the system rebooted, the packets caught in the middle of a communication flow will be dropped. It is after watching a movie that it is interesting.
Could you guys show the output of:

~# sudo ethtool -a eth0
~# sudo ethtool -S eth0 | grep -v 0$

it will show us the negotiated speed and the interface statistics (Long, reason I grepped out all lines showing 0 at the end).

Other question: What switch do you guys use?
I have rarely seen any issues with my Vero device while connected to a decent switch (Using this one: https://www.amazon.com/dp/B00H1OM0BA/ref=psdc_281414_t3_B0046BAVQ2 myself).

ethtool command not found