Mesa 7i96s a little jitter

Hi linuxcnc, I have a small amount of jitter in my newly upgraded set up. I have followed along with this post forum.linuxcnc.org/38-general-linuxcnc-q...7i76e-solved?start=0
 and generated the attached Halscope. It looks to me that my dpll phase error is quite poor in comparison to pcw’s. When I ping the mesa I have a range of .14 to .35 ms. So I believe as per the instructions here forum.linuxcnc.org/27-driver-boards/3559...ethernet-mesa-boards
I should enter sudo ethtool -C eno1 rx-usecs 0 into command line? It returns command not found. So if someone would be so kind to confirm I’m on the right track and tell me please how to find ethtool.
thankyou

Apologies I forgot to add

Linux 2.8.4
Hp 8200 elite
Debian 10

And the intel 82579lm onboard Ethernet

I am surprised that ethtool is not included in the 2.8.4 distribution
To add ethtool:

sudo apt install ethtool

Thanks JT. So I should do this as well as performing the ‘ethtool -C eno1 rx-usecs 0’ ?
Reason i ask is per tommylight instructions above he opens with “ ---Warning : IF using this tutorial, NEVER edit the /etc/network/interfaces file as mentioned in the official documents, using BOTH causes a lot of issues, so use this OR the other, never both!!! ---

Hi Tommy totally understand why you put that there and I for one appreciate it! I just wanted to make sure I wasn’t going to fall into the trap seen as I already followed your very helpful guide… so to round this off along with adding ‘ethtool -C eno1 rx-usecs 0’ which I have now done I should also do as JT says and disable RX IRQ coalescing? Thanks again for taking the time to help.

Sorry one more thing. When I entered ethtool -C eno1 rx-usecs 0 into command line it just went to another command line without any additional info - is there a command to check that this has actually achieved what was intended?