Description

The QFX5200-32c 2 member virtual chassis with multiple VCP ports has a dedicated buffer allocation for each VC ports. When removing one of the VCP ports and relocating it to a different slot, the switch does not release the buffer allocation for the old port after its removed. 

Symptoms

Current VC port location: 

{master:0}
root@qfx5200-32> show virtual-chassis 

Virtual Chassis ID: 3872.c0be.becd
Virtual Chassis Mode: Enabled
                                                Mstr           Mixed Route Neighbor List
Member ID  Status   Serial No    Model          prio  Role      Mode  Mode ID  Interface
0 (FPC 0)  Prsnt    WH0218160077 qfx5200-32c-32q 128  Master*      N  VC   1  vcp-255/0/0
                                                                           1  vcp-255/0/1
                                                                           1  vcp-255/0/2
                                                                           1  vcp-255/0/3
1 (FPC 1)  Prsnt    WH0218350005 qfx5200-32c-32q 128  Backup       N  VC   0  vcp-255/0/0
                                                                           0  vcp-255/0/1
                                                                           0  vcp-255/0/2
                                                                           0  vcp-255/0/3

New port location:

{master:0}
root@qfx5200-32> show virtual-chassis 

Virtual Chassis ID: 3872.c0be.becd
Virtual Chassis Mode: Enabled
                                                Mstr           Mixed Route Neighbor List
Member ID  Status   Serial No    Model          prio  Role      Mode  Mode ID  Interface
0 (FPC 0)  Prsnt    WH0218160077 qfx5200-32c-32q 128  Master*      N  VC   1  vcp-255/0/0
                                                                           1  vcp-255/0/22
                                                                           1  vcp-255/0/29
                                                                           1  vcp-255/0/4
1 (FPC 1)  Prsnt    WH0218350005 qfx5200-32c-32q 128  Backup       N  VC   0  vcp-255/0/0
                                                                           0  vcp-255/0/22
                                                                           0  vcp-255/0/29
                                                                           0  vcp-255/0/4
After moving the VC ports, the PFE will not release the allocated buffer for vcp-255/0/1 or vcp-255/0/2 and it will assign a new buffer for replacement ports vcp-255/0/22 and vcp-255/0/29

Solution

To avoid this issue, make sure you delete the VCP ports from CLI first using "request virtual-chassis vc-port delete pic-slot <> port <>"  before moving the VCP ports physically. 

If the ports were moved before deleting them from CLI, then a complete system reboot will fix this issue.