ALE OmniSwitch stack does not form due to incompatible licenses

Today I saw an interesting behaviour of two Alcatel-Lucent Enterprise OmniSwitch 6450. Both switches has been configured as a stack, but one of the switches showed a flashing ID after the startup, and the stack was not formed. While I checked the logs and the status of the stack, I noticed that the slot number was incorrect. Furthermore the status showed “INC-LIC”.

-> show stack topology
                                         Link A  Link A          Link B  Link B
NI      Role      State   Saved  Link A  Remote  Remote  Link B  Remote  Remote
                          Slot   State   NI      Port    State   NI      Port
----+-----------+--------+------+-------+-------+-------+-------+-------+-------
   1 PRIMARY     RUNNING    1    UP       1001   StackB  DOWN        0        0
1001 PASS-THRU   INC-LIC    2    DOWN        0        0  UP          1   StackA

-> show log swlog
<snip>
THU MAR 03 13:07:29 2016  STACK-MANAGER    info == SM == Stack Port A Status Changed: DOWN
THU MAR 03 13:07:29 2016  STACK-MANAGER    info == SM == NI 0 down notification sent to LAG
THU MAR 03 13:08:41 2016  STACK-MANAGER    info == SM == Stack Port A Status Changed: UP
THU MAR 03 13:08:41 2016  STACK-MANAGER    info == SM == Stack Port A MAC Frames TX/RX Enabled
THU MAR 03 13:08:42 2016  STACK-MANAGER    info  Retaining Module Id for slot 2 unit 0 as 1
THU MAR 03 13:08:46 2016  STACK-MANAGER    info == SM == An element enters passthru mode (incompatible license)
<snip>

According to the stack status and the switch logs, there seems to be a problem with the licenses. So I checked the installed licenses on both switches. On switch showed Metro license:

-> show license info
 NI          Application           License Type                Time Left
-----------+---------------------+---------------------------+--------------
 1              METRO                 Permanent                   0
 1              10G                   Permanent                   0
 1001           10G                   Permanent                   0

The other switch not:

 -> show license info
 NI          Application           License Type                Time Left
-----------+---------------------+---------------------------+--------------
 1              10G                   Permanent                   0

Don’t be confused because of the slot numbering. I pulled the stacking cable.

The solution was easy: I removed the metro license and after a reboot of the switch, from which I removed the license, the stack formed properly.

-> show stack topology
                                         Link A  Link A          Link B  Link B
NI      Role      State   Saved  Link A  Remote  Remote  Link B  Remote  Remote
                          Slot   State   NI      Port    State   NI      Port
----+-----------+--------+------+-------+-------+-------+-------+-------+-------
   1 SECONDARY   RUNNING    1    UP          2   StackB  DOWN        0        0
   2 PRIMARY     RUNNING    2    DOWN        0        0  UP          1   StackA