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

Hmm, Debian's wiki is as out of date as Linuxcnc's.

Untested, but I think the the correct way to bring a interface up should be:
ip link set dev enp2s0 up

So I think the interfaces file should be
pre-up /sbin/ip link set dev $IFACE up
post-down /sbin/ip link set dev $IFACE down

I did find a igc kernel patch Intel was involved in so I think its OK to ignore:Subject: [PATCH] net/igc: disable EEE by default on I225/226
>
> I226-V devices can hang when EEE is enabled. Explicitly disable EEE during
> initialization of the device, as the Linux and FreeBSD kernel drivers do.Also, I think we should disable all power mangerment in grub:
pcie_aspm.policy=performance pcie_port_pm=off

So many gotchas!

Hello i am very new to linuxcnc but dicovered that when you start the ethercat slave before the PC is loaded you will loss connection to internet. The work around for me is first start the pc and then the slave.

Linuxcnc 2.9.4, dual ethernet network realtek rtl,
When first start pc wired connection 1 is connected and 2 is not seen. Connecting slave to connection 2 is not seen but working.
When first start slave wire connection 1 is not connected and 2 is not seen, slave is working. There is no internet.