N5K with N2K FEX vPC

panMar 17, 2025

1. Attach FEX

1.1 Configure FEX on both N5Ks

Since vPC is not enabled yet, N5K-1 configured with FEX will attach the FEX and N5K-2 won’t.

feature fex

interface Ethernet1/43
  no shut
  switchport mode fex-fabric
  fex associate 100
  
interface Ethernet1/44
  no shut
  switchport mode fex-fabric
  fex associate 101

feature fex

interface Ethernet1/43
  no shut
  switchport mode fex-fabric
  fex associate 100
  
interface Ethernet1/44
  no shut
  switchport mode fex-fabric
  fex associate 101

On N5K-2, FEX state is connected. But you can’t check its details which means N5K-1 manages the attached FEX control information. If you check the FEX uplink interface SFP as a test, you can’t get the information.

N5K-2# show fex
  FEX         FEX           FEX              FEX              Fex       
Number    Description      State            Model            Serial     
————————————————————————
—       ——–               Offline    N2K-C2232PP-10GE   SSI17230KCP
—       ——–               Offline    N2K-C2232PP-10GE   SSI170505TQ

N5K-2# show int fex
     Fabric     Fabric       Fex       FEX           Fex      
Fex  Port      Port State    Uplink    Model         Serial    
—————————————————————
100   Eth1/43        Active     6      N2K-C2232PP-10GE   SSI170505TQ
101   Eth1/44        Active     6      N2K-C2232PP-10GE   SSI17230KCP

N5K-2# show int eth1/43 transceiver fex-fabric 
Ethernet1/43 : sfp information is not available

1.2 FEX Attachment State Change Process

Logs on N5K-1. N5K-2 goes through the same process but doesn’t mange the FEX.

Mar 18 10:55:18 N5K-1 %FEX-5-FEX_ENABLED: FEX Enabled
Mar 18 10:55:21 N5K-1 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 5 of Fex 0 that is connected with Ethernet1/43 changed its status from Created to Discovered
Mar 18 10:56:04 N5K-1 %ETHPORT-5-IF_DOWN_CFG_CHANGE: Interface Ethernet1/43 is down(Config change)
Mar 18 10:56:04 N5K-1 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 5 of Fex 0 that is connected with Ethernet1/43 changed its status from Discovered to Created
Mar 18 10:56:05 N5K-1 %ETHPORT-5-SPEED: Interface Ethernet1/43, operational speed changed to 10 Gbps
Mar 18 10:56:05 N5K-1 %ETHPORT-5-IF_DUPLEX: Interface Ethernet1/43, operational duplex mode changed to Full
Mar 18 10:56:05 N5K-1 %ETHPORT-5-IF_RX_FLOW_CONTROL: Interface Ethernet1/43, operational Receive Flow Control state changed to off
Mar 18 10:56:05 N5K-1 %ETHPORT-5-IF_TX_FLOW_CONTROL: Interface Ethernet1/43, operational Transmit Flow Control state changed to off
Mar 18 10:56:08 N5K-1 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 5 of Fex 0 that is connected with Ethernet1/43 changed its status from Created to Discovered
Mar 18 10:56:11 N5K-1 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 5 of Fex 100 that is connected with Ethernet1/43 changed its status from Discovered to Configured
Mar 18 10:56:11 N5K-1 %ETHPORT-5-IF_DOWN_INITIALIZING: Interface Ethernet1/43 is down (Initializing)
Mar 18 10:56:14 N5K-1 %ETHPORT-5-SPEED: Interface Ethernet1/43, operational speed changed to 10 Gbps
Mar 18 10:56:14 N5K-1 %ETHPORT-5-IF_DUPLEX: Interface Ethernet1/43, operational duplex mode changed to Full
Mar 18 10:56:14 N5K-1 %ETHPORT-5-IF_RX_FLOW_CONTROL: Interface Ethernet1/43, operational Receive Flow Control state changed to off
Mar 18 10:56:14 N5K-1 %ETHPORT-5-IF_TX_FLOW_CONTROL: Interface Ethernet1/43, operational Transmit Flow Control state changed to off
Mar 18 10:56:14 N5K-1 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 0 of Fex 100 that is connected with Ethernet1/43 changed its status from Configured to Fabric Up
Mar 18 10:56:15 N5K-1 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 5 of Fex 100 that is connected with Ethernet1/43 changed its status from Fabric Up to Connecting
Mar 18 10:56:15 N5K-1 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 5 of Fex 100 that is connected with Ethernet1/43 changed its status from Connecting to Active
Mar 18 10:56:15 N5K-1 %ETHPORT-5-IF_UP: Interface Ethernet1/43 is up in mode Fex Fabric

When I shut the port towards FEX, I got the following logs.

Mar 19 01:35:15 N5K-1 %ETHPORT-5-IF_DOWN_CFG_CHANGE: Interface Ethernet1/43 is down(Config change)
Mar 19 01:35:15 N5K-1 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 5 of Fex 100 that is connected with Ethernet1/43 changed its status from Active to Disconnected
Mar 19 01:35:15 N5K-1 %NOHMS-2-NOHMS_ENV_FEX_OFFLINE: FEX-100 Off-line (Serial Number SSI170505TQ)
Mar 19 01:35:15 N5K-1 %PFMA-2-FEX_STATUS: Fex 100 is offline
Mar 19 01:35:15 N5K-1 %ETHPORT-5-IF_DOWN_INTERFACE_REMOVED: Interface Ethernet100/1/1 is down (Interface removed)
Mar 19 01:35:15 N5K-1 %ETHPORT-5-IF_DOWN_INTERFACE_REMOVED: Interface Ethernet100/1/2 is down (Interface removed)
……
Mar 19 01:35:16 N5K-1 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 5 of Fex 100 that is connected with Ethernet1/43 changed its status from Disconnected to Configured
Mar 19 01:35:16 N5K-1 %ETHPORT-5-IF_DOWN_ADMIN_DOWN: Interface Ethernet1/43 is down (Administratively down)

The logs on the N5K-2 is as follows. It takes 32 seconds for N2K to be back online on the other N5K.

Mar 19 01:27:33 N5K-2 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 6 of Fex 100 that is connected with Ethernet1/43 changed its status from Active to Disconnected
Mar 19 01:27:34 N5K-2 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 6 of Fex 100 that is connected with Ethernet1/43 changed its status from Disconnected to Fabric Up
Mar 19 01:27:35 N5K-2 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 6 of Fex 100 that is connected with Ethernet1/43 changed its status from Fabric Up to Connecting
Mar 19 01:27:35 N5K-2 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 6 of Fex 100 that is connected with Ethernet1/43 changed its status from Connecting to Active
Mar 19 01:27:40 N5K-2 %ETHPORT-5-IF_DOWN_NONE: Interface Ethernet100/1/1 is down (Transceiver Absent)
Mar 19 01:27:40 N5K-2 %ETHPORT-5-IF_DOWN_NONE: Interface Ethernet100/1/2 is down (Transceiver Absent)
……

The FEX 100 is hidden from N5K-1 and shown on N5K-2.

N5K-1# show fex
  FEX         FEX           FEX              FEX              Fex       
Number    Description      State            Model            Serial     
————————————————————————
101        FEX0101                Online    N2K-C2232PP-10GE   SSI17230KCP

N5K-2# show fex
  FEX         FEX           FEX              FEX              Fex       
Number    Description      State            Model            Serial     
————————————————————————
100        FEX0100                Online    N2K-C2232PP-10GE   SSI170505TQ
—       ——–               Offline    N2K-C2232PP-10GE   SSI17230KCP

Now I unshut the link towards FEX on N5K-1, I got the following log.

Mar 19 01:50:05 N5K-1 %ETHPORT-5-IF_ADMIN_UP: Interface Ethernet1/43 is admin up.
Mar 19 01:50:09 N5K-1 %ETHPORT-5-SPEED: Interface Ethernet1/43, operational speed changed to 10 Gbps
Mar 19 01:50:09 N5K-1 %ETHPORT-5-IF_DUPLEX: Interface Ethernet1/43, operational duplex mode changed to Full
Mar 19 01:50:09 N5K-1 %ETHPORT-5-IF_RX_FLOW_CONTROL: Interface Ethernet1/43, operational Receive Flow Control state changed to off
Mar 19 01:50:09 N5K-1 %ETHPORT-5-IF_TX_FLOW_CONTROL: Interface Ethernet1/43, operational Transmit Flow Control state changed to off
Mar 19 01:50:09 N5K-1 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 0 of Fex 100 that is connected with Ethernet1/43 changed its status from Configured to Fabric Up
Mar 19 01:50:09 N5K-1 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 5 of Fex 100 that is connected with Ethernet1/43 changed its status from Fabric Up to Connecting
Mar 19 01:50:09 N5K-1 %FEX-5-FEX_PORT_STATUS_NOTI: Uplink-ID 5 of Fex 100 that is connected with Ethernet1/43 changed its status from Connecting to Active
Mar 19 01:50:09 N5K-1 %ETHPORT-5-IF_UP: Interface Ethernet1/43 is up in mode Fex Fabric

FEX is still attached to N5K-2.

N5K-1# show fex
  FEX         FEX           FEX              FEX              Fex       
Number    Description      State            Model            Serial     
————————————————————————
101        FEX0101                Online    N2K-C2232PP-10GE   SSI17230KCP
—       ——–             Connected    N2K-C2232PP-10GE   SSI170505TQ

1.3 FEX Show Command Output

Show FEX interface related information.

N5K-1# show fex
  FEX         FEX           FEX              FEX              Fex       
Number    Description      State            Model            Serial     
————————————————————————
100        FEX0100                Online    N2K-C2232PP-10GE   SSI170505TQ
101        FEX0101                Online    N2K-C2232PP-10GE   SSI17230KCP

N5K-1# show interface fex
     Fabric     Fabric       Fex       FEX           Fex      
Fex  Port      Port State    Uplink    Model         Serial    
—————————————————————
100   Eth1/43        Active     5      N2K-C2232PP-10GE   SSI170505TQ
101   Eth1/44        Active     5      N2K-C2232PP-10GE   SSI17230KCP

N5K-1# show fex 100 detail
FEX: 100 Description: FEX0100   state: Online
  FEX version: 7.3(13)N1(1) [Switch version: 7.3(13)N1(1)]
  FEX Interim version: 7.3(13)N1(1)
  Switch Interim version: 7.3(13)N1(1)
  Extender Serial: SSI170505TQ
  Extender Model: N2K-C2232PP-10GE,  Part No: 73-12533-05
  Card Id: 82, Mac Addr: 70:10:5c:6f:83:82, Num Macs: 64
  Module Sw Gen: 21  [Switch Sw Gen: 21]
  Post level: complete
  Pinning-mode: static    Max-links: 1
  Fabric port for control traffic: Eth1/43
  FCoE Admin: false
  FCoE Oper: true
  FCoE FEX AA Configured: false
  Fabric interface state:
    Eth1/43 – Interface Up. State: Active
  Fex Port        State  Fabric Port
       Eth100/1/1  Down        None
       Eth100/1/2  Down        None
       Eth100/1/3  Down        None
       Eth100/1/4  Down        None
       Eth100/1/5  Down     Eth1/43
       Eth100/1/6  Down        None
       Eth100/1/7  Down        None
       Eth100/1/8  Down        None
       Eth100/1/9  Down        None
      Eth100/1/10  Down        None
      Eth100/1/11  Down        None
      Eth100/1/12  Down        None
      Eth100/1/13  Down        None
      Eth100/1/14  Down        None
      Eth100/1/15  Down        None
      Eth100/1/16  Down        None
      Eth100/1/17  Down        None
      Eth100/1/18  Down        None
      Eth100/1/19  Down        None
      Eth100/1/20  Down        None
      Eth100/1/21  Down        None
      Eth100/1/22  Down        None
      Eth100/1/23  Down        None
      Eth100/1/24  Down        None
      Eth100/1/25  Down        None
      Eth100/1/26  Down        None
      Eth100/1/27  Down        None
      Eth100/1/28  Down        None
      Eth100/1/29  Down        None
      Eth100/1/30  Down        None
      Eth100/1/31  Down        None
      Eth100/1/32  Down        None
Logs:
03/18/2025 10:58:10.191892: Module register received
03/18/2025 10:58:10.193770: Image Version Mismatch
03/18/2025 10:58:10.194972: Registration response sent
03/18/2025 10:58:10.195253: Requesting satellite to download image
03/18/2025 11:03:40.660036: Image preload successful.
03/18/2025 11:03:42.054991: Deleting route to FEX
03/18/2025 11:03:42.062651: Module disconnected
03/18/2025 11:03:42.064043: Module Offline
03/18/2025 11:05:11.702730: Module register received
03/18/2025 11:05:11.705782: Registration response sent
03/18/2025 11:05:11.746490: create module inserted event.
03/18/2025 11:05:11.747440: Module Online Sequence
03/18/2025 11:05:17.382921: Module Online

N5K-1# show fex 101 detail
……
  Fabric interface state:
    Eth1/44 – Interface Up. State: Active
  Fex Port        State  Fabric Port
       Eth101/1/6  Down     Eth1/44
……

Show the transceiver info on N5K side and N2K side. They are different if using different SFPs.

——————————————————-
| N5K transceiver | <---> | N2K transceiver fex-fabric|
——————————————————-

N5K-1# show int eth1/43 transceiver 
Ethernet1/43
    transceiver is present
    type is SFP-10G-AOC1M       
    name is CISCO-AVAGO     
    part number is AFBR-2CAR01Z-CS1
    revision is B1  
    serial number is AVP2331K0VK-B   
    nominal bitrate is 10300 MBit/sec
    Link length supported for AOC is 1 m
    cisco id is 3
    cisco extended id number is 4

N5K-1# show int eth1/43 transceiver fex-fabric 
Ethernet1/43
    transceiver is present
    type is SFP-10G-AOC1M       
    name is CISCO-AVAGO     
    part number is AFBR-2CAR01Z-CS1
    revision is B1  
    serial number is AVP2331K0VK-A   
    nominal bitrate is 10300 MBit/sec
    Link length supported for AOC is 1 m
    cisco id is 3
    cisco extended id number is 4

Show FEX inventory and environment information.

N5K-1# show inventory fex 100
NAME: “FEX 100 CHASSIS”, DESCR: “N2K-C2232PP-10GE  CHASSIS”
PID: N2K-C2232PP-10GE  , VID: V03 , SN: SSI170505TQ

NAME: “FEX 100 Module 1”, DESCR: “Fabric Extender Module: 32x10GE, 8x10GE Superv
isor”
PID: N2K-C2232PP-10GE  , VID: V03 , SN: FOC17132TH4

NAME: “FEX 100 Fan 1”, DESCR: “Fabric Extender Fan module”
PID: N2K-C2232-FAN-B   , VID: N/A , SN: N/A

NAME: “FEX 100 Power Supply 1”, DESCR: “Fabric Extender AC power supply”
PID: N2200-PAC-400W-B  , VID: V03 , SN: LIT231533LY

NAME: “FEX 100 Power Supply 2”, DESCR: “Fabric Extender AC power supply”
PID: N2200-PAC-400W-B  , VID: V03 , SN: LIT231533LF

N5K-1# show environment fex 100


Temperature Fex 100:
—————————————————————–
Module   Sensor     MajorThresh   MinorThres   CurTemp     Status
                    (Celsius)     (Celsius)    (Celsius)         
—————————————————————–
1        Center     90            80           29          ok             
1        Fan-side   90            80           34          ok             
1        Port-side  90            80           37          ok             
1        Die-1      125           100          44          ok             
1        Control-1  70            56           33          ok             


Fan Fex: 100:
——————————————————
Fan             Model                Hw         Status
——————————————————
Chassis         N2K-C2232-FAN-B      —         ok
PS-1            N2200-PAC-400W-B     —         ok
PS-2            N2200-PAC-400W-B     —         no power source


Power Supply Fex 100:
—————————————————————————
Voltage: 12 Volts
—————————————————–
PS  Model                Power       Power     Status
                         (Watts)     (Amp)           
—————————————————–
1   N2200-PAC-400W-B      396.00     33.00     ok                  
2   —                        —        —     fail/shutdown       


Mod Model                Power     Power       Power     Power       Status
                         Requested Requested   Allocated Allocated         
                         (Watts)   (Amp)       (Watts)   (Amp)               
— ——————-  ——-   ———-  ——— ———-  ———-
1    N2K-C2232PP-10GE    88.80     7.40        88.80     7.40        powered-up


Power Usage Summary:
——————–
Power Supply redundancy mode:                 redundant
Power Supply redundancy operational mode:     Non-redundant

2. Form vPC

feature vpc
feature lacp

vpc domain 50
  peer-switch
  role priority 10
  peer-keepalive destination 192.168.1.2 source 192.168.1.1 vrf default
  delay restore 150
  peer-gateway
  ip arp synchronize
  
interface Ethernet1/45
  no shut
  description vPC Keepalive to N5K-2
  no switchport
  ip address 192.168.1.1/30
  
interface Ethernet1/46
  no shut
  description vPC peerlink to N5K-2
  switchport
  switchport mode trunk
  channel-group 12 mode active
  
interface port-channel12
  description vPC peerlink to N5K-2
  switchport mode trunk
  spanning-tree port type network
  vpc peer-link

feature vpc
feature lacp

vpc domain 50
  peer-switch
  role priority 15
  peer-keepalive destination 192.168.1.1 source 192.168.1.2 vrf default
  delay restore 150
  peer-gateway
  ip arp synchronize
  
interface Ethernet1/45
  no shut
  description vPC Keepalive to N5K-1
  no switchport
  ip address 192.168.1.2/30
  
interface Ethernet1/46
  no shut
  description vPC peerlink to N5K-1
  switchport
  switchport mode trunk
  channel-group 12 mode active
  
interface port-channel12
  description vPC peerlink to N5K-1
  switchport mode trunk
  spanning-tree port type network
  vpc peer-link

The vPC status is as follows.

N5K-1
N5K-2

N5K-1# show vpc
Legend:
                (*) – local vPC is down, forwarding via vPC peer-link

vPC domain id                     : 50  
Peer status                       : peer adjacency formed ok      
vPC keep-alive status             : peer is alive                 
Configuration consistency status  : success 
Per-vlan consistency status       : success                       
Type-2 consistency status         : success 
vPC role                          : primary                       
Number of vPCs configured         : 0   
Peer Gateway                      : Enabled
Peer gateway excluded VLANs       : –
Dual-active excluded VLANs        : –
Graceful Consistency Check        : Enabled
Operational Layer3 Peer-router    : Disabled
Auto-recovery status              : Enabled (timeout = 240 seconds)

vPC Peer-link status
———————————————————————
id   Port   Status Active vlans    
—   —-   —— ————————————————–
1    Po12   up     1    

N5K-2# show vpc
Legend:
                (*) – local vPC is down, forwarding via vPC peer-link

vPC domain id                     : 50  
Peer status                       : peer adjacency formed ok      
vPC keep-alive status             : peer is alive                 
Configuration consistency status  : success 
Per-vlan consistency status       : success                       
Type-2 consistency status         : success 
vPC role                          : secondary                     
Number of vPCs configured         : 0   
Peer Gateway                      : Enabled
Peer gateway excluded VLANs       : –
Dual-active excluded VLANs        : –
Graceful Consistency Check        : Enabled
Operational Layer3 Peer-router    : Disabled
Auto-recovery status              : Enabled (timeout = 240 seconds)

vPC Peer-link status
———————————————————————
id   Port   Status Active vlans    
—   —-   —— ————————————————–
1    Po12   up     1  

2.2 Configure vPC for FEX

Configure the following on both N5Ks.

interface port-channel100
  switchport mode fex-fabric
  no lacp suspend-individual
  fex associate 100
  vpc 100
  
interface port-channel101
  switchport mode fex-fabric
  no lacp suspend-individual
  fex associate 101
  vpc 101
  
interface Ethernet1/43
  channel-group 100
  
interface Ethernet1/44
  channel-group 101

Now N2Ks can be managed from either of the N5Ks.

N5K-1# show fex
  FEX         FEX           FEX              FEX              Fex       
Number    Description      State            Model            Serial     
————————————————————————
100        FEX0100                Online    N2K-C2232PP-10GE   SSI170505TQ
101        FEX0101                Online    N2K-C2232PP-10GE   SSI17230KCP

N5K-2# show fex
  FEX         FEX           FEX              FEX              Fex       
Number    Description      State            Model            Serial     
————————————————————————
100        FEX0100                Online    N2K-C2232PP-10GE   SSI170505TQ
101        FEX0101                Online    N2K-C2232PP-10GE   SSI17230KCP

I got the following log when I make the configuration change.

Mar 19 02:57:23 N5K-2 %$ VDC-1 %$ %FEX-2-FEX_PORT_STATUS_CRIT: Uplink-ID 6 of Fex 100 that is connected with Ethernet1/43 changed its status from Fabric Up to Incompatible-Topology
Mar 18 02:57:25 N5K-2 %$ VDC-1 %$ %SATCTRL-FEX100-2-SATCTRL: FEX-100 Module 1: Cold boot
Mar 19 02:58:16 N5K-2 %$ VDC-1 %$ %PFMA-2-FEX_STATUS: Fex 100 is online
Mar 19 02:58:16 N5K-2 %$ VDC-1 %$ %NOHMS-2-NOHMS_ENV_FEX_ONLINE: FEX-100 On-line
Mar 19 02:58:16 N5K-2 %$ VDC-1 %$ %PFMA-2-FEX_STATUS: Fex 100 is online

Now the FEX interfaces are in the show vpc output.

N5K-1# show vpc
Legend:
                (*) – local vPC is down, forwarding via vPC peer-link

vPC domain id                     : 50  
Peer status                       : peer adjacency formed ok      
vPC keep-alive status             : peer is alive                 
Configuration consistency status  : success 
Per-vlan consistency status       : success                       
Type-2 consistency status         : success 
vPC role                          : primary                       
Number of vPCs configured         : 66  
Peer Gateway                      : Enabled
Peer gateway excluded VLANs       : –
Dual-active excluded VLANs        : –
Graceful Consistency Check        : Enabled
Operational Layer3 Peer-router    : Disabled
Auto-recovery status              : Enabled (timeout = 240 seconds)

vPC Peer-link status
———————————————————————
id   Port   Status Active vlans    
—   —-   —— ————————————————–
1    Po12   up     1                                                         

vPC status
—————————————————————————-
id     Port        Status Consistency Reason                     Active vlans
—— ———– —— ———– ————————– ———–
100    Po100       up     success     success                    –           
101    Po101       up     success     success                    –           
101376 Eth100/1/1  down*  Not         Consistency Check Not      –           
                          Applicable  Performed                              
101377 Eth100/1/2  down*  Not         Consistency Check Not      –           
                          Applicable  Performed                              
101378 Eth100/1/3  down*  Not         Consistency Check Not      –  
……

2.3 Configure Host vPC

Configure VLAN, SVI interface, HSRP and port-channel towards Host.

N5K-1
N5K-2

feature interface-vlan 
feature hsrp 

vlan 120

interface Vlan120
  no shutdown
  ip address 10.1.120.2/24
  hsrp version 2
  hsrp 120 
    preempt
    priority 105
    ip 10.1.120.1

interface Ethernet100/1/5
  no shut
  switchport
  switchport mode access 
  switchport access vlan 120
  spanning-tree port type edge
  channel-group 120 mode active
  
interface port-channel120
  switchport access vlan 120
  spanning-tree port type edge

feature interface-vlan 
feature hsrp 

vlan 120

interface Vlan120
  no shutdown
  ip address 10.1.120.3/24
  hsrp version 2
  hsrp 120 
    preempt
    ip 10.1.120.1

interface Ethernet100/1/5
  no shut
  switchport
  switchport mode access 
  switchport access vlan 120
  spanning-tree port type edge
  channel-group 120 mode active
  
interface port-channel120
  switchport access vlan 120
  spanning-tree port type edge

The status of Po120 is as follows:

N5K-1# show port-channel summary | in 120
120   Po120(SD)   Eth      LACP      Eth100/1/5(D)  
N5K-1# show vpc | in 120
1    Po12   up     1,120                                                     
262263 Po120       down*  Not         Consistency Check Not      – 
N5K-1# show int po120
port-channel120 is down (No operational members)

 vPC Status: Down, vPC number: 262263 [packets forwarded via vPC peer-link]
  Hardware: Port-Channel, address: 0000.0000.0000 (bia 0000.0000.0000)
  MTU 1500 bytes,  BW 100000 Kbit, DLY 10 usec
  reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, medium is broadcast
  Port mode is access
  auto-duplex, 10 Gb/s
  Input flow-control is off, output flow-control is on
  Switchport monitor is off 
  EtherType is 0x8100 
  Members in this channel: Eth100/1/5
……

If I configure vPC under Po120, I got this error.

N5K-1(config-if)# vpc 120
ERROR: Operation failed: [vPC already exists] 