How can I avoid receiving the “Configuration does not match the port capability” error message when enabling “switchport mode fex-fabric”?

This error message is generated because the port is not FEX capable:

N7K-2(config)#interface ethernet 9/5
N7K-2(config-if)#switchport mode fex-fabric
ERROR: Ethernet9/5: Configuration does not match the port capability

In order to resolve this problem, check the port capabilities by using the show interface ethernetcommand.

For example:

N7K-2#show interface ethernet 9/5 capabilities
Ethernet9/5
  Model:                 N7K-M132XP-12
  Type (SFP capable):    10Gbase-(unknown)
  Speed:                 10000
  Duplex:                full
  Trunk encap. type:     802.1Q
  Channel:               yes
  Broadcast suppression: percentage(0-100)
  Flowcontrol:           rx-(off/on),tx-(off/on)
  Rate mode:             shared
  QOS scheduling:        rx-(8q2t),tx-(1p7q4t)
  CoS rewrite:           yes
  ToS rewrite:           yes
  SPAN:                  yes
  UDLD:                  yes
  Link Debounce:         yes
  Link Debounce Time:    yes
  MDIX:                  no
  Pvlan Trunk capable:   no
  Port Group Members:    1,3,5,7
  TDR capable:           no
  FabricPath capable:    no
  Port mode:             Routed,Switched
  FEX Fabric:            no
  dot1Q-tunnel mode:     yes

From this output of the show interface ethernet 9/5 capabilitiescommand, you can see FEX Fabric: no. This verifies that the port is not FEX capable. In order to resolve this problem, upgrade the EPLD imagesto Cisco NX-OS Release 5.1(1) or later.