SecureStack 'Detach' & 'ConfigMismatch' Symptoms

[FAQ_User]

Article ID: 5876

Products
C5, C3, C2-Series
B5, B3, B2-Series
A2-Series

Symptoms
Port has Detach oper status
'show port status'
"Detach"
Stack member has Config Mismatch switch status
'show switch'
"ConfigMismatch"

Cause
One or more ports may display an Oper Status of "Detach" in the output of a 'show port status' query, while the switch itself displays a Switch Status of "ConfigMismatch" in a 'show switch' or 'show switch ' query:

B2(rw)->show port status
Alias Oper Admin Speed
Port (truncated) Status Status (bps) Duplex Type
--------- ------------ ------- ------- --------- ------- ------------
ge.1.1 Up Up 1.0G full BaseT RJ45
. . .
ge.1.48 Down Up N/A N/A BaseT RF45
. . .
fe.2.1 Detach Up N/A N/A BaseT RJ45/PoE
. . .
ge.2.52 Detach Up N/A N/A SFP
lag.0.1 Up Up 2.0G full lag
. . .
lag.0.6 Down Up lag
B2(rw)->show switch
Management Preconfig Plugged-in Switch Code
Switch Status Model ID Model ID Status Version
------ ------------ ------------- ------------- --------------------- --------
1 Mgmt Switch B2G124-48 B2G124-48 OK 04.00.60
2 Stack Member B2H124-48P B2H124-48P ConfigMismatch 04.00.60
B2(rw)->
There are two reasons stated in the Configuration Guides for a port to have a "Detach" status:

1. Preconfiguring a virtual switch and then adding a physical switch of a different type to the stack as that unit number (or replacing a pre-existing switch with a switch of a different type, due to RMA or other reason) will trigger this condition if any configured functionality cannot be supported on the physical switch.
2. Clearing a license from (or not applying a license to) a stack member unit while the master unit has a configured license, will trigger this condition on the member unit.

In either case, the affected unit's ports will be detached from the stack (that is, will not pass traffic).

Solution
Depending upon which of the above items applies,

1. You must clear the mismatch ('show switch', 'clear switch...', 'set switch member...') or install the correct/expected switch model instead of the incorrect switch model, before the new device will properly join the stack.
2. If the stack manager is licensed then all stack units must be licensed, or unlicensed devices will not properly join the stack. See 5834 and 5781 for guidance regarding the 'show license', 'clear license', and 'set license' commands. See 10081 for a possible bug which could expire a permanent license.

Also note this change implemented as of C5/C3/B5/B3 firmware 6.42.10.0016, in reference to a 'Detach' state due to stack instability:
Release notes state, in the 'Firmware Changes and Enhancements' section:
Added the capability to detect unidirectional stacking communication failures. This mode of failure may have resulted in units being in a permanently detached state. On detection, the failing unit will automatically reset and rejoin the stack.