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Force Consistency Check??

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Justin Lenhart
Level 1
Level 1

‎12-17-2013 09:54 AM

I'm trying to create a VPC between two 5ks to a single server but when I bring them up the VPC never changes from the down state.... Below shows the config of each and some show commands. It seems like 5k2 hasn't performed a consistency check but 5k1 has and it shows successful.

5k1


int eth 1/12

channel-group 204 mode active

!

interface port-channel204

  switchport access vlan 1072

  speed 10000

  vpc 204

!

5k1# show port-channel summary

Flags:  D - Down        P - Up in port-channel (members)

        I - Individual  H - Hot-standby (LACP only)

        s - Suspended   r - Module-removed

        S - Switched    R - Routed

        U - Up (port-channel)

        M - Not in use. Min-links not met

--------------------------------------------------------------------------------

Group Port-       Type     Protocol  Member Ports

      Channel

--------------------------------------------------------------------------------

1     Po1(SU)     Eth      NONE      Eth1/31(P) 

204   Po204(SD)   Eth      LACP      Eth1/12(I)

!

5k1# show vpc br

Legend:

                (*) - local vPC is down, forwarding via vPC peer-link

vPC domain id                   : 5  

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       : 9  

Peer Gateway                    : Disabled

Dual-active excluded VLANs      : -

Graceful Consistency Check      : Enabled

vPC Peer-link status

---------------------------------------------------------------------

id   Port   Status Active vlans   

--   ----   ------ --------------------------------------------------

1    Po1    up     1-9,33,36,43,46,329,1050-1059,1070,1072-1073,1101-       

                   1116,1997                                                

vPC status

----------------------------------------------------------------------------

id     Port        Status Consistency Reason                     Active vlans

------ ----------- ------ ----------- -------------------------- -----------                    

204    Po204       down*  success     success                    -          

5k2

5k2# show run int port 204

!Command: show running-config interface port-channel204

!Time: Tue Dec 17 09:35:46 2013

version 5.1(3)N1(1a)

interface port-channel204

  switchport access vlan 1072

  speed 10000

  vpc 204

!

interface Ethernet1/12

  channel-group 204 mode active

!

5k2# show port-channel summary

Flags:  D - Down        P - Up in port-channel (members)

        I - Individual  H - Hot-standby (LACP only)

        s - Suspended   r - Module-removed

        S - Switched    R - Routed

        U - Up (port-channel)

        M - Not in use. Min-links not met

--------------------------------------------------------------------------------

Group Port-       Type     Protocol  Member Ports

      Channel

--------------------------------------------------------------------------------

1     Po1(SU)     Eth      NONE      Eth1/32(P)  

204   Po204(SD)   Eth      LACP      Eth1/12(I)  

!

5k2# show vpc brief

Legend:

                (*) - local vPC is down, forwarding via vPC peer-link

vPC domain id                   : 5  

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       : 41 

Peer Gateway                    : Disabled

Dual-active excluded VLANs      : -

Graceful Consistency Check      : Enabled

vPC Peer-link status

---------------------------------------------------------------------

id   Port   Status Active vlans   

--   ----   ------ --------------------------------------------------

1    Po1    up     1-9,33,36,43,46,329,1050-1059,1070,1072-1073,1101-       

                   1116,1997                                                

vPC status

----------------------------------------------------------------------------

id     Port        Status Consistency Reason                     Active vlans

------ ----------- ------ ----------- -------------------------- -----------                               

204    Po204       down*  Not         Consistency Check Not      -          

                          Applicable  Performed                             

1 person had this problem
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1 Accepted Solution

Accepted Solutions

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Steve Fuller
Level 9
Level 9

‎12-19-2013 05:10 AM

Hi Justin,

The Link Aggregate you've configured is what's referred to as dynamic, and as such it will use the Link Aggregation Control Protocol (LACP) to negotiate with the link partner i.e., the server, on a number of parameters to use for the forming and control of the aggregate.

What we can see from the show port-channel summary command is that the links are in the Individual (I) state. This is usually an indication that the remote device is not sending LACPDU frames. You should be able to see this by checking the Recv column in the output of show lacp counters interface port-channel 204 command. It will most likely be 0.

If that's the case you'll need to check with the server guys how they have the aggregate configured. It must be using NIC teaming software supporting something along the lines of IEEE 802.3ad Dynamic (HP), IEEE 802.3ad or mode=4 (Linux) or LACP with VMware ESXi.

If you're connecting to a server whose OS only supports static link aggregation e.g., VMware ESXi prior to version 5.1, then you should change the Nexus configuration to use static Link Aggregation with the channel-group 204 mode on command under the Ethernet1/12 interface. Note that you can't change the keywords used with the channel-group command, but have to remove it and add it back using the on keyword.

Regards

View solution in original post

2 Replies 2

Go to solution
Steve Fuller
Level 9
Level 9

‎12-19-2013 05:10 AM

Hi Justin,

The Link Aggregate you've configured is what's referred to as dynamic, and as such it will use the Link Aggregation Control Protocol (LACP) to negotiate with the link partner i.e., the server, on a number of parameters to use for the forming and control of the aggregate.

What we can see from the show port-channel summary command is that the links are in the Individual (I) state. This is usually an indication that the remote device is not sending LACPDU frames. You should be able to see this by checking the Recv column in the output of show lacp counters interface port-channel 204 command. It will most likely be 0.

If that's the case you'll need to check with the server guys how they have the aggregate configured. It must be using NIC teaming software supporting something along the lines of IEEE 802.3ad Dynamic (HP), IEEE 802.3ad or mode=4 (Linux) or LACP with VMware ESXi.

If you're connecting to a server whose OS only supports static link aggregation e.g., VMware ESXi prior to version 5.1, then you should change the Nexus configuration to use static Link Aggregation with the channel-group 204 mode on command under the Ethernet1/12 interface. Note that you can't change the keywords used with the channel-group command, but have to remove it and add it back using the on keyword.

Regards

Go to solution
Justin Lenhart
Level 1
Level 1
In response to Steve Fuller

‎12-19-2013 12:04 PM

steve, you were right on. Thanks for the extremely detailed response!

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