Description

This is a Resolution Guide, which steps you through the method to check the Virtual Chassis status and troubleshoot virtual-chassis members if they are not in an Active/Healthy (Present) state.

Symptoms

Note: This guide assumes that you have the Virtual Chassis configured. For configuration examples on configuring a Virtual Chassis, refer to Virtual Chassis Overview for Switches. Although the outputs presented here are for Juniper EX Series legacy platforms, the same outputs apply for ELS devices for EX Series and QFX Series switches.

 

This article helps you to:

  • Understand and interpret Virtual Chassis member status

  • Understand and interpret Virtual Chassis member roles

  • Verify that the Virtual Chassis is in Active (in a healthy/present) state

  • Troubleshoot Virtual Chassis members if they are not in Active (Present) state

Solution

This solution includes the following topics:

 

(Click the link to jump directly to the topic.)

 

Definition - Virtual Chassis Member Status

The output of the command show virtual-chassis status reports the status of each member.

root@virtual-chassis> show virtual-chassis status 

Virtual Chassis ID: 6eb0.0094.e64b
                    Mastership            Neighbor List  
Member ID  Status    Serial No     Model       priority Role    ID Int
0 (FPC 0)  Prsnt     BR0208233776  ex4200-24f  128      Backup   1 vcp-0      
1 (FPC 1)  Prsnt     BR0209456997  ex4200-24f  128      Master*  3 vcp-0      
                                                               	 0 vcp-1      
2 (FPC 2)  Prsnt     BR0208233803  ex4200-24f  128      Linecard 3 vcp-1      
3 (FPC 3)  Inactive  BR0209457019  ex4200-24f  128      Linecard 2 vcp-0      
           Unprvsnd  BP0208180138  ex4200-48t
4 (FPC 4)  NotPrsnt  BP0208180138  ex4200-48t

Member ID for next new member: 5 (FPC 5)
 

There are four possible valid Member Status states:

  • Prsnt (Present)

The status Prsnt indicates that all switches are part of a single Virtual Chassis and hence can be managed as a single logical device. This status also indicates that members have established physical and logical connections between them.

  • NotPrsnt (Not-Present)

The status NotPrsnt indicates that the switch is physically disconnected from the existing Virtual Chassis. These devices cannot be managed as a single logical device since they do not have an established physical connection with an existing Virtual Chassis.

  • Inactive

The status Inactive indicates that the members have established a physical connection but are unable to establish logical connections. These devices can be managed as a single logical device since they have an established physical connection but they cannot be an Active member of the Virtual Chassis because they have not established a logical connection with an existing Virtual Chassis.

  • UnPrvsnd (Not-Provisioned)

Pre-Provisioning is a method for defining Virtual Chassis members and roles. The status UnPrvsnd indicates that the switch cannot synchronize with an existing pre-provisioned Virtual Chassis. The Virtual Chassis member that has an "Unprvsnd" status has not been configured as part of the Virtual Chassis yet.

For more information about the show virtual chassis status command, refer to show virtual-chassis.

 

Definition - Virtual Chassis Member Roles

The output of the command show virtual-chassis status also reports the role of each member.

root@virtual-chassis> show virtual-chassis status

Virtual Chassis ID: 6eb0.0094.e64b
                    Mastership            Neighbor List  
Member ID  Status    Serial No     Model       priority Role    ID Int
0 (FPC 0)  Prsnt     BR0208233776  ex4200-24f  128      Backup   1 vcp-0      
1 (FPC 1)  Prsnt     BR0209456997  ex4200-24f  128      Master*  3 vcp-0      
                                                               	 0 vcp-1      
2 (FPC 2)  Prsnt     BR0208233803  ex4200-24f  128      Linecard 3 vcp-1      
3 (FPC 3)  Inactive  BR0209457019  ex4200-24f  128      Linecard 2 vcp-0      
           Unprvsnd  BP0208180138  ex4200-48t                                                      
4 (FPC 4)  NotPrsnt  BP0208180138  ex4200-48t

Member ID for next new member: 5 (FPC 5)
 

There are three possible valid roles that a switch can have in a Virtual Chassis:

  • Primary: This member governs the entire Virtual Chassis and:

    • Manages the member switches

    • Runs Junos OS for the switches as a primary Routing Engine

    • Runs the chassis management processes and control protocols

    • Represents all the member switches that are interconnected within the Virtual Chassis configuration. (The hostname and other properties that you assign to this switch during setup apply to all members of the Virtual Chassis configuration.)

  • Backup: This member acts as a standby to the primary Routing Engine and:

    • Maintains a state of readiness to take over the primary Routing Engine role if the primary fails

    • Runs Junos OS for the switches as a backup Routing Engine

    • Synchronizes with the primary in terms of protocol states, forwarding tables, and other information, so that it is prepared to preserve routing information and maintain network connectivity without disruption in case the primary is unavailable

  • Linecard: These members contribute to multiplying physical attributes:

    • Runs only a subset of Junos OS

    • Does not run the chassis control protocols

    • Can detect certain error conditions (such as an unplugged cable) on any interfaces that have been configured on it through the primary

For more information about these roles, refer to Understanding Virtual Chassis Components.

 

Verify that the VC is in a healthy state and troubleshoot if it is not

The following steps detail how to verify that a Virtual Chassis is in a healthy state and how to rescue an unhealthy Virtual Chassis.

A Virtual Chassis can be identified as "healthy" based on the roles and the status shown in the show virtual chassis status output.

The definition of a healthy Virtual Chassis is as follows:

  • A Virtual Chassis is considered healthy when there is a minimum of two members, Primary and Backup, where one member acts as the Primary Routing Engine and the other member acts as the Backup Routing Engine. In a two-member Virtual Chassis, no member should be configured as a Linecard. 

  • Depending on the platform, a Virtual Chassis can have a maximum of 10 members, composed of two Routing Engines and 8 Linecards.

  • All the members must have a status of Prsnt.

 

Perform the following steps:

  1. Run the command show virtual chassis status:

root@virtual-chassis> show virtual-chassis    

Virtual Chassis ID: 6eb0.0094.e64b
                          Mastership            Neighbor List  
Member ID   Status    Serial No       Model         priority   Role      ID  Interface
0 (FPC 0)   Prsnt     BR0208233776    ex4200-24f    128        Linecard   1  vcp-0      
1 (FPC 1)   Prsnt     BR0209456997    ex4200-24f    128        Master*    3  vcp-0      
                                                                 	  0  vcp-1      
2 (FPC 2)   Prsnt     BR0208233803    ex4200-24f    128        Backup     3  vcp-1      

Member ID for next new member: 3 (FPC 3)

Do you see both a 'Primary' and a 'Backup' with the status Prsnt ?

  • Yes - Continue to Step 2.

  • No   - Jump to Step 4.

  1. If you have Linecards, do you see all the Linecard members with the status Prsnt?

  • Yes - Continue to Step 3.

  • No -  Jump to Step 4.

  1. Since all the members are present, your Virtual Chassis is active. Sometimes administrators want a designated member to be the primary. Is your expected primary currently the primary?

  • Yes - At this point, your Virtual Chassis is in a healthy state as all the members have a status of Prsnt. 

Tip: It is strongly recommended that you enable graceful Routing Engine switchover (GRES) on your VC. For more information, see Understanding Graceful Routing Engine Switchover. You may also want to perform the following check on the VCPs: Verifying That the Virtual Chassis Ports (VCPs) Are Operational.

  • Doesn’t Matter - At this point, your Virtual Chassis is in a healthy state as all the members have a status of Prsnt.

Tip: It is strongly recommended that you enable GRES on your VC. For more information, see KB21368 - [EOL/EOE] GRES FAQ for EX Virtual Chassis [juniper.net].

You may also want to perform the following check on the VCPs: Verifying That the Virtual Chassis Ports (VCPs) Are Operational.

  1. What is the status of the member that is not in the Prsnt state?
  • Inactive – Go to Step 5.

  • Not-Prsnt – Go to Step 7.

  • Unprvsnd – Go to Step 11.

  1. [Member is Inactive] Run the command show version.

Typically, when a member is inactive, it indicates that all the members of the switch are not running the same Junos OS version. The following command will display the Junos OS version for all the members, which are physically connected (including Present and Inactive members).

{master:1}[edit]
root@virtual-chassis> show version
fpc0:
--------------------------------------------------------------------------
Hostname: EX4200-VC
Model: ex4200-48t
JUNOS Base OS boot [11.1R1.10]
JUNOS Base OS Software Suite [11.1R1.10]
JUNOS Kernel Software Suite [11.1R1.10]
JUNOS Crypto Software Suite [11.1R1.10]
JUNOS Online Documentation [11.1R1.10]
JUNOS Enterprise Software Suite [11.1R1.10]
JUNOS Packet Forwarding Engine Enterprise Software Suite [11.1R1.10]
JUNOS Routing Software Suite [11.1R1.10]
JUNOS Web Management [11.1R1.10]

fpc1:
--------------------------------------------------------------------------
Hostname: EX4200-VC
Model: ex4200-24f
JUNOS Base OS boot [10.2R3.10]
JUNOS Base OS Software Suite [10.2R3.10]
JUNOS Kernel Software Suite [10.2R3.10]
JUNOS Crypto Software Suite [10.2R3.10]
JUNOS Online Documentation [10.2R3.10]
JUNOS Enterprise Software Suite [10.2R3.10]
JUNOS Packet Forwarding Engine Enterprise Software Suite [10.2R3.10]
JUNOS Routing Software Suite [10.2R3.10]
JUNOS Web Management [10.2R3.10]

fpc2:
--------------------------------------------------------------------------
Hostname: EX4200-VC
Model: ex4200-24f
JUNOS Base OS boot [10.2R3.10]
JUNOS Base OS Software Suite [10.2R3.10]
JUNOS Kernel Software Suite [10.2R3.10]
JUNOS Crypto Software Suite [10.2R3.10] JUNOS Online Documentation [10.2R3.10] JUNOS Enterprise Software Suite [10.2R3.10]
JUNOS Packet Forwarding Engine Enterprise Software Suite [10.2R3.10]
JUNOS Routing Software Suite [10.2R3.10]
JUNOS Web Management [10.2R3.10] 
 

Are all the Members running the same Junos OS versions?

  1. Then run the command show virtual chassis status to see if the switch has joined the other members of the Virtual Chassis. Restart at Step 1 to verify the overall health.

  2. [Member became NotPrsnt or is missing from the Virtual Chassis.] NotPrsnt means loss of physical connectivity.

For a Virtual Chassis that is composed of EX4300 and EX4300MP, the Virtual Chassis will not form unless the command request virtual-chassis mode ieee-clause-82 mixed is issued on the EX4300 devices. You must use the 40G ports at the back to form this mixed Virtual Chassis.

If this is not the case, console into the affected switch to troubleshoot the issue. Run the command show virtual-chassis status’ and 'show virtual-chassis vc-port.

What is the role of that particular member?

  • Isolated Switch reports Role as Linecard – Continue to Step 8.

  • Isolated Switch reports Role as Primary – Continue to Step 10.

  1. [Isolated switch reports the Role as Linecard.] Re-activate the Virtual Chassis to make that switch a stand-alone switch by running the following command:

root@EX4200-VC# run request virtual-chassis reactivate 

If it is still stuck in the "Linecard" role, follow the steps in KB33879 - Routing Engine stuck in "Linecard" role [juniper.net].

Run the command show virtual-chassis status. Now has the affected switch joined the other members of the Virtual Chassis?

  • Yes – Restart at Step 1 to verify overall health.

  • No – Continue to Step 9.

  1. Try rebooting the affected switch. Run the command show virtual-chassis status. Now has the affected switch joined the other members of the Virtual Chassis?

  1. [Isolated Switch reports Role as Primary but not joining existing Virtual Chassis].

For example, in the output below, FPC 0 (Expected Back-Up: BR0208233776) reports its role as Primary but the member is not joining the existing Virtual Chassis.

root@virtual-chassis> show virtual-chassis    

Virtual Chassis ID: 6eb0.0094.e64b
                         Mastership            Neighbor List  
Member ID  Status   Serial No      Model         priority   Role          ID  Interface
0 (FPC 0)  Prsnt    BR0208233776   ex4200-24f    128        Master*           

Member ID for next new member: 1 (FPC 1)
 

Perform the following steps if the switch is an isolated Primary:

  1. Confirm whether the Virtual Chassis cables are firmly seated. Then run the command show virtual chassis status to see if the switch has joined the other members of the Virtual Chassis. If so, restart at Step 1 to verify status.

  2. Try a different Virtual Chassis cable. Then run the command show virtual chassis status to see if the switch has joined the other members of the Virtual Chassis. If so, restart at Step 1 to verify status.

  3. Try performing a factory-default on the affected switch, FPC 0 (Expected Back-Up: BR0208233776):

    root@Ex4200-VC# load factory-default

    For more information, refer to KB11159 - [EX] How to Revert Back to Default Factory Configuration [juniper.net].

  4. Then run the command show virtual chassis status to see if the switch has joined the other members of the Virtual Chassis. If so, restart at Step 1 to verify the overall health.

If it is still isolated, collect the information specified in KB20569 - [EX/QFX] How to collect logs and files from standalone and Virtual Chassis/VCF devices [juniper.net], and open a case with your technical support representative.

  1. [Member became Unprvsnd (Not-provisioned)].

For example, in the output below, the expected back-up (BR0208233776) became Not-Provisioned (Unprvsnd):

root@virtual-chassis> show virtual-chassis    

Preprovisioned Virtual Chassis
Virtual Chassis ID: 6eb0.0094.e64b
                                          Mastership            Neighbor List  
Member ID  Status     Serial No       Model         priority    Role      ID  Interface
 	   Unprvsnd   BR0208233776    ex4200-24f                         
1 (FPC 1)  Prsnt      BR0209456997    ex4200-24f    128         Master*    3  vcp-0      
                                                            				                                    
2 (FPC 2)  Prsnt      BR0208233803    ex4200-24f    128         Backup     3  vcp-1      
 

A status of Unprvsnd means that the member is interconnected with the Virtual Chassis but is not specified in the preprovisioned configuration file.

Verify that the Virtual Chassis pre-provisioning configuration is correct. In most cases, entering the serial number with the incorrect case is the issue; the pre-provisioning configuration is case-sensitive.

Below is an example pre-provisioning configuration. Note how the syntax for the serial number is incorrect.

set virtual-chassis preprovisioned
set virtual-chassis member 0 role routing-engine
set virtual-chassis member 0 serial-number br0208233776 <-----incorrect
set virtual-chassis member 1 role routing-engine
set virtual-chassis member 1 serial-number BR0209456997
set virtual-chassis member 2 role line-card
set virtual-chassis member 2 serial-number BR0208233803
set virtual-chassis member 3 role line-card
set virtual-chassis member 3 serial-number BR0209457019

For additional help with pre-provisioning, refer to the following examples in Configuring an EX2300, EX3400, EX4300, or EX4400 Virtual Chassis with a Preprovisioned Configuration File.

  1. After correcting the pre-provisioning configuration, run the command show virtual-chassis status. Are any members still showing the status as Unprvsnd?

For additional Information about Virtual Chassis, refer to Understanding EX Series Virtual Chassis.

 

Modification History

2019-09-13: Updated step 8 in the solution. Also, updated hyperlinks to technical documentation.
2021-03-25: Updated the article terminology to align with Juniper's Inclusion & Diversity initiatives.
2021-12-28: Updated article to maintain the current definitions on Tech Documentation and other data on ELS.