Debian tries to connect to the internet on EtherCAT network device?

Hi,

I use a "Odroid H4" as master and it has two network interfaces. Perfect for LinuxCNC with EtherCAT and cabled networking. However, I'm having the issue that both network interfaces shows up as if they both can connect to the internet: 


Two things annoy me:
1. Is there a way to rename these devices? The naming is kinda useless as it is and it bothers my OCD, preferably i'd call one Internet and the other EtherCAT or something like that, but i've seem to have tried everything google suggests me to rename them, without any luck...apparently not the correct one yet, ideas?
2. The top network card is the one connected to the internet...but every time the machine starts, it attempts to connect to "Internet connection" via the bottom one. These attempts causes the EtherCAT bus to reset every minute or so...to solve this i have to press "Disconnect" at the lower card and press "Internet connection" at the upper card...at every start of the system Can i somehow mark the EtherCAT card as "hands off!" for internet-stuff? And the internet is automagically connected via the upper one? First i thought "easy fix", i'll just swap cables and use it the other way around....BUT lo and behold, the problem was the exact same, but now the interfaces was just switched around...ideas?

I know this isn't "LinuxCNC and ethercat specifics", but i assume others here have had the same issues, so i hope it is ok...

/Thomas

not sure but you could try adding this to /etc/network/interfacesauto eno1
iface eno1 inet dhcp
    hardware-irq-coalesce-rx-usecs 0
replace eno1 with the NIC name reported by ip a for ethercat
Restart the network

Also add this to your boot parameters using grub-customizer to disable energy efficient internet igb.EEE=0

rodw wrote:

iface eno1 inet dhcp
    hardware-irq-coalesce-rx-usecs 0

Ehm.... it worked! Thanks! The networkinterface for EtherCAT is no longer in the list of networks and now the internet connection defaults to the proper interface, and EtherCAT works like a charm now...but....why did that work? :-D I don't understand since nothing in that configuration seems indicate "oh, by the way, this will hide the interface from UI and prevent InternetConnection from trying to use it"...i've looked up the hardware-irq-coalesce-rx-usecs parameter and that only seems to be some sort of tuning, not something that should do what it just did....

Sorry, i'm just trying to understand it... the worst part is when something works, and i don't understand why it works

PS: I also disabled the power-stuff in GRUB as you suggested. Thanks!

/Thomas

That can't be right? Maybe it works, but you normally don't want nor need an IP-address on the ethercat interface.
Here is my config for I226-V in /etc/network/interfaces.
The i226 uses the Intel igc driver, the energy-efficient mode is off by default, so the igb.EEE=0 is not needed and also is for the igb driver, not the igc.
You can rename the nic with a .link file, google it the best tip there.