How to Set Manually the Intel® Ethernet Network Adapter XXV710 Port Speed Using Ethtool on CentOS* 7.7

Unable to set manually the network card port speed using ethtool. The network card port works at 1GbE if the link partner is 1GpE.

1. Verify the current advertised modes. Open a Terminal (Command line window)
2. Type the command: ethtool -s advertise
3. Then, conclude all bit masks associated with these modes and setting advertised to this value according to the Bitmask values. Available at Ethtool(8) - Linux* Manual Page.