Description

This article explains the troubleshooting steps to take when an FPC gets detached from a Virtual-chassis post reboot/any activity.

Symptoms

>>One of the FPCs in the Linecard role is detached from the Virtual-chassis after its reboot. Console access should work fine for the detached FPC.

 

In the below example, FPC3 is detached from the VC:

root@virtual-chassis> show virtual-chassis status
Preprovisioned Virtual Chassis
Virtual Chassis ID: 5bcd.fda4.57c9
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    PE3121240371 ex4300-48t     129   Master*      N  VC   1  vcp-255/1/0
                                                                           4  vcp-255/1/2
1 (FPC 1)  Prsnt    PE3121240035 ex4300-48t     129   Backup       N  VC   0  vcp-255/1/0
                                                                           2  vcp-255/1/2
2 (FPC 2)  Prsnt    PE3121240895 ex4300-48t       0   Linecard     N  VC   3  vcp-255/1/0
                                                                           1  vcp-255/1/2
3 (FPC 3)  NotPrsnt PE3121240690 ex4300-48t       0   Linecard     N  VC   2  vcp-255/1/0.  <<<<<<<<<<<<<<< Shows FPC3 in "NotPrsnt" state.
                                                                           4  vcp-255/1/2
4 (FPC 4)  Prsnt    PE3121300156 ex4300-48t       0   Linecard     N  VC   0  vcp-255/1/0
                                                                           3  vcp-255/1/2

 

 

Solution

1) Check the virtual-chassis status as shown in the above symptom (Prsnt/NotPrsnt).

 

>show virtual-chassis

>show virtual-chassis status

 

 

2) Check if the virtual-chassis is configured on the detached FPC and on the Master as well.

 

>show configuration virtual-chassis

 

Example:

virtual-chassis {
    auto-sw-update {
        package-name /var/tmp/jinstall-ex-4300-18.1R3-S11.3-signed.tgz;
    }
    preprovisioned;
    no-split-detection;
    member 0 {
        role routing-engine;
        serial-number PE3121240371;
    }
    member 1 {
        role routing-engine;
        serial-number PE3121240035;
    }
    member 2 {
        role line-card;
        serial-number PE3121240895;
    }
    member 3 {
        role line-card;
        serial-number PE3121240690;    >>>>>>>>>>> FPC 3 is configured as VC on the master.
    }
    member 4 {
        role line-card;
        serial-number PE3121300156;

 

3) Run the below command on the FPC to check the vc-port status.

 

root@virtual-chassis> show virtual-chassis vc-port

{linecard3}
root@virtual-chassis>

If the output is empty as shown , go to step 4.

 

 

4) Remove the VC configuration from FPC and re-configure it back. Execute the below commands from the Shell mode.

 

To remove the VC config:

 

>start shell user root

 

%cd /config/vchassis/

%rm *

%ps aux | grep vccp >>>>This will give you the process ID (pid)

kill <pid>

 

 

Reactivate the VC:

 

>request virtual-chassis re-activate

 

 

Re-configure the VC by setting the vc-ports:

 

>request virtual-chassis vc-port set pic-slot <pic_number> port <port_number>

 

For example, if the pic is 1 and the ports are 0 and 2, then the commands are below:

 

>request virtual-chassis vc-port set pic-slot 1 port 0

>request virtual-chassis vc-port set pic-slot 1 port 2

 

 

5) Once the VC is reconfigured on the FPC, you should get the in-band access back and FPC should be in "Prsnt" state in the VC.

 

After getting the in-band access, if incase one of the vc-ports shows down, then try to convert vc-port to normal port and back to vc-port again to see if that brings the port up.

 

Example:
root@virtual-chassis@> show virtual-chassis vc-port
fpc3:
--------------------------------------------------------------------------
Interface   Type              Trunk  Status       Speed        Neighbor
or                             ID                 (mbps)       ID  Interface
PIC / Port
1/0         Configured         -1    Up           40000        0   vcp-255/1/0
1/2         Configured         -1    down         40000        2   vcp-255/1/2 <<<<<<<<<<<<.  Shows vc-port 1/2 in "down" state.
1/1         Configured               Absent
1/3         Configured               Absent

 

The command used to convert the VCP to its original uplink interface (example: et-3/1/2) is as follows:

 

>request virtual-chassis vc-port delete pic-slot 1 port 2

 

The command used to convert the normal port back to VCP:

 

>request virtual-chassis vc-port set pic-slot 1 port 2

 

 

You should be able to see the port status as "up" on the FPC.

 

Modification History

2024-06-21 : Article Created