X440G2-48p-10G4 to VSP8404 fabric attach help

[Bongs]

I am trying to add an edge Exos switch to a fabric network. Fabric attach seem to be established between exos and vsp but the management vlan is showing None.
# show fabric attach elements
Fabric Attach Mode: Standalone Proxy
Mgmt Auto
System Id Port Type VLAN Tag Provision
----------------------------- ------- ---------------- ---- --- --------------
64-6a-52-ac-4c-00-00-00-00-c3 49 Server None Mix Disabled
on the VSP

show fa elements
************************************************************************************
Command Execution Time: Fri Feb 11 19:46:55 2022 SAST
************************************************************************************

====================================================================================================
Fabric Attach Discovery Elements
====================================================================================================
MGMT ELEM ASGN
PORT    TYPE      VLAN   STATE       SYSTEM ID                                      AUTH AUTH
----------------------------------------------------------------------------------------------------
1/4        proxy        0            T / D      00:04:96:cd:36:85:00:01:00:31       AP       N

Fabric attach assignments show to be active, but the vlan/isid is showing N/A
show fabric attach assignments
Fabric Attach Mode: Standalone Proxy
Port VLAN VLAN Name Type    ISID/NSI Status
------- ---- -------------------------------- ------- -------- --------
        100     managemnt Static    N/A        Active
        900     VLAN_900   Static      N/A      Active

[Anonymous]

Your EXOS switch is in standalone proxy mode instead of the default client mode.
I guess you used the very unintuitive "configure fabric attach uplink <port>" command.

Type "configure fabric attach uplink none" to switch back to client mode.

[Ludovico_Steven]

Is showing None, because no FA mgmt VLAN I-SID was configured on the VSP port 1/4.
The command is :
int gig 1/4
   fa management i-sid <i-sid> c-vid <vlan-id>
exit

[JamesM2]

I see the EXOS switch has fa authentication off. Can you do a show fa interface on the VSP. 
EXOS doesn't use FA authentication by default, while VOSS does.

[Bongs]

sho fa interface
************************************************************************************
Command Execution Time: Sat Feb 12 09:08:58 2022 SAST
************************************************************************************

====================================================================================================
Fabric Attach Interfaces
====================================================================================================
INTERFACE    SERVER      MGMT      MGMT    MSG AUTH      MSG AUTH
                         STATUS     ISID           CVID       STATUS             KEY
----------------------------------------------------------------------------------------------------
Port1/4          enabled       0                 0            enabled              ****
Mlt15             enabled       0                 0             enabled             ****
Mlt16             enabled       0                 0             enabled             ****

sho fa elements
************************************************************************************
Command Execution Time: Sat Feb 12 09:13:08 2022 SAST
************************************************************************************

====================================================================================================
Fabric Attach Discovery Elements
====================================================================================================
                             MGMT                                                                         ELEM ASGN
PORT       TYPE   VLAN    STATE     SYSTEM ID                                  AUTH AUTH
----------------------------------------------------------------------------------------------------
1/4           proxy   0           T / D     00:04:96:cd:36:85:00:01:00:31    AP        N
1/15        proxy   100       T / D     bc:ad:ab:96:b4:00:20:00:00:01    AP        N
1/20        proxy   100      T / D      bc:ad:ab:6b:d8:00:20:00:00:01    AP        N
Fabric Attach Authentication Detail
====================================================================================================
           ELEM OPER        ASGN OPER
PORT AUTH STATUS   AUTH STATUS
----------------------------------------------------------------------------------------------------
1/4 successAuth          none

1/15 successAuth      successAuth
1/20 successAuth      successAuth