ethtool -S <network device> | egrep "err|fail"
I get the following errors:
tx_lost_interrupt: 225 rx_alloc_fail: 36297
What is, tx_lost_interrupt and rx_alloc_fail ?
Do these errors indicate a real network problem?
Those are NIC- or driver-specific extended statistics, so it would be important to know the type of the network interface used and/or the name of the driver module used with it.
However, at least in kernel version 4.14.85, it looks like the string
tx_lost_interrupt appears only in the Intel i40e NIC driver. This seems to be the patch that originally added that statistic to the driver.
It looks like it counts the times a software workaround was applied to a case of a lost hardware interrupt. I could not find any further description, but it looks like a workaround for a NIC hardware bug to me...
rx_alloc_fail, on the other hand, looks like it indicates the number of times the driver failed to allocate a memory buffer for received packet(s). That might indicate that your system is under some amount of memory pressure, and could use more RAM.