Issue

• Trying to set any of the 802-3-ethernet properties returns an error that the property cannot be changed.

  # nmcli connection show em1 | grep 802-3
  connection.type:                        802-3-ethernet
  802-3-ethernet.port:                    --
  802-3-ethernet.speed:                   0
  802-3-ethernet.duplex:                  --
  802-3-ethernet.auto-negotiate:          yes
  802-3-ethernet.mac-address:             --
  802-3-ethernet.cloned-mac-address:      --
  802-3-ethernet.mac-address-blacklist:   
  802-3-ethernet.mtu:                     auto
  802-3-ethernet.s390-subchannels:        
  802-3-ethernet.s390-nettype:            --
  802-3-ethernet.s390-options:            
  802-3-ethernet.wake-on-lan:             1 (default)
  802-3-ethernet.wake-on-lan-password:    --
  
  
  # nmcli connection modify em1 802-3-ethernet.auto-negotiate off
  Error: failed to modify 802-3-ethernet.auto-negotiate: the property can't be changed.
  
  # nmcli connection modify em1 802-3-ethernet.speed 100
  Error: failed to modify 802-3-ethernet.speed: the property can't be changed.
  
  # nmcli connection modify em1 802-3-ethernet.duplex full
  Error: failed to modify 802-3-ethernet.duplex: the property can't be changed.
  
  
  # ethtool -s em1 autoneg off speed 100 duplex full
  # echo $?
  0