dmesg | grep xgbe
]]>I'm guessing you know how to set those options permanently in /etc/modprobe.d using a .conf file.
If you actually have a very high speed connection the higher spec Ethernet cable could end up being an important factor. Again, just a guess, but it could pay off.
]]>Have you searched dmesg for related errors?
I would suggest if you're only using cat 5 network cable to upgrade to at least a cat 6e or better yet cat7 replacement.
Did you try changing your speed setting with ethtool?
Did you try changing your MTU setting, try setting jumbo frames at 9000.
Try this command and see if you can change your speeds afterwards:
# modprobe -r ixgbe; sleep 3; modprobe ixgbe msi=0 msix=0
Try disabling or removing your other Ethernet adapter, either in the bios or phsically removing it if it is an add in card.
That's all I got.
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