Troubleshooting a strictly provisioned, mismatched MAC address

Cause

When switches are strictly provisioned, it is possible to enter an incorrect type or incorrect MAC address. If this occurs, the switch does not match the intended configuration entry and stacking attempts to add this switch as a new “plug-and-go” switch. If the stacking configuration already has 4 switches, then the “plug-and-go” fails.

The following example shows a stack with 3 members. There is a new J9728A switch that is supposed to be member 4; however, the MAC address was mis-typed, and there is an “opening” for a plug-and-go at member 4. It will join as member 4.

Action

This shows the stack before boot.

Displaying a stack with 3 members

switch(stacking)# show stacking

Stack ID         : 00031cc1-de4d87c0
MAC Address      : 1cc1de-4dc765
Stack Topology   : Ring021560
Stack Status     : Active
Uptime           : 0d 0h 56m
Software Version : WB.15.11.0000x

Mbr
ID  Mac Address   Model                                 Pri Status
--- ------------- ------------------------------------- --- --------------
1   1cc1de-4d87c0 HPE J9727A 2920-24G-PoE+-2SFP+ Switch  200 Standby
2   1cc1de-4dc740 HPE J9727A 2920-24G-PoE+-2SFP+ Switch  128 Commander
3   1cc1de-4dbd40 HPE J9726A 2920-24G Switch             128 Member

This shows that, after booting, the switch is joined as member 4:

Displaying a member joining the stack

switch(config)# show stacking

Stack ID : 00031cc1-de4d87c0
MAC Address : 1cc1de-4dc765
Stack Topology : Ring
Stack Status : Active
Uptime : 0d 1h 11m
Software Version : WB.15.11.0000x

Mbr
ID  Mac Address   Model                                  Pri Status
--- ------------- -------------------------------------- --- -------------
1   1cc1de-4d87c0 HPE J9727A 2920-24G-PoE+-2SFP+ Switch   200 Standby
2   1cc1de-4dc740 HPE J9727A 2920-24G-PoE+-2SFP+ Switch   128 Commander
3   1cc1de-4dbd40 HPE J9726A 2920-24G Switch              128 Member
4   1cc1de-4d79c0 HPE J9728A 2920-48G-4SFP+ Switch        128 Member

To correct this issue:

Write down the correct MAC address.
Remove the member that was added using plug-and-go with the strictly provisioned, mismatched MAC address as shown in the following example.
Update the strictly provisioned entry with the correct MAC address.
Boot the switch.

Removing a member and updating the entry with a MAC address

switch(config)# stacking member 4 remove reboot

The specified stack member will be removed from the stack and
its configuration will be erased. The resulting configuration
will be saved. The stack member will be rebooted and join as
a new member. Continue [y/n]? Y

switch(config)#: stacking member 4 type J9728A mac-address

This shows that member 4 has joined the stack.

switch(config)# show stacking

Stack ID         : 00031cc1-de4d87c0
MAC Address      : 1cc1de-4dc765
Stack Topology   : Ring
Stack Status     : Active
Uptime           : 0d 1h 19m
Software Version : WB.15.11.0000x

Mbr
ID  Mac Address   Model                                  Pri Status
--- ------------- -------------------------------------- --- ---------------
1   1cc1de-4d87c0 HPE J9727A 2920-24G-PoE+-2SFP+ Switch   200  Standby
2   1cc1de-4dc740 HPE J9727A 2920-24G-PoE+-2SFP+ Switch   128  Commander
3   1cc1de-4dbd40 HPE J9726A 2920-24G-2SFP+ Switch        128  Member
4   1cc1de-4d79c0 HPE J9728A 2920-48G-4SFP+ Switch        175  Member