module ex-ethernet {
  namespace "http://example.com/ethernet";
  prefix "eth";

  import ietf-interfaces {
    prefix if;
  }
  import iana-if-type {
    prefix ianaift;
  }

  // configuration and state parameters for Ethernet interfaces
  augment "/if:interfaces/if:interface" {
    when "if:type = 'ianaift:ethernetCsmacd'";
    container ethernet {
      choice transmission-params {
        case auto {
          leaf auto-negotiate {
            type empty;
          }
        }
        case manual {
          leaf duplex {
            type enumeration {
              enum "half";
              enum "full";
            }
          }

          leaf speed {
            type enumeration {
              enum "10Mb";
              enum "100Mb";
              enum "1Gb";
              enum "10Gb";
            }
          }
        }
      }
      leaf duplexx {
        type enumeration {
          enum "half";
          enum "full";
        }
        config false;
      }
      // other Ethernet-specific params...
    }
  }
}