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Resolution Guide - EX - Troubleshoot Virtual Chassis (VC)

  [KB21064] Show Article Properties


Summary:

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


Symptoms:
  • Understand and interpret Virtual Chassis Member status
  • Understand and interpret Virtual Chassis Member roles
  • Verify Virtual Chassis is Active (in a healthy/present) state
  • Troubleshoot Virtual Chassis members if they are not in a Active (Present) State

Note:
  This guide assumes you have the Virtual Chassis configured.
For examples on how to configure a Virtual Chassis, refer to
http://www.juniper.net/techpubs/en_US/junos/information-products/pathway-pages/ex-series/virtual-chassis-4200-4500.html#configuration.

Cause:

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@EX4200-VC# run 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. Hence it can be managed as a single logical device. The status Prsnt states members have established physical & logical connections between them.

NotPrsnt (Not-Present);
The status NotPrsnt indicates that the particular switch has been disconnected from the existing Virtual Chassis. These devices cannot be managed as a single logical device since they do not have established Physical connection with an existing Virtual Chassis.

Inactive:
The status Inactive states that those members have established physical connections, but are unable to establish logical connections. These devices can be managed as a single logical device since they have established physical connection but cannot be an Active member of the Virtual chassis since they have not established 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 particular switch cannot synchronize with an existing pre-provisioned Virtual Chassis. These devices cannot be managed as a single logical device since they have not established a physical connection with an existing Virtual Chassis.


For more information on the show virtual chassis status command, refer to http://www.juniper.net/techpubs/en_US/junos10.4/topics/reference/command-summary/show-virtual-chassis-status.html.

Definition - Virtual Chassis Member Roles

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


root@EX4200-VC# run 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 be in a Virtual Chassis:

Master:

This member which governs the entire Virtual Chassis:

  • Serves as the Master (Preferred) Routing Engine for the Virtual Chassis
  • Manages the entire Virtual Chassis
  • Runs the chassis management processes and network control protocols
  • Calculates and maintains the forwarding table and distributes it to the local CPU, and then to Packet Forwarding Engines (PFEs) in all member switches
  • Receives and transmits routing information
  • Represents all member switches (the hostname that was assigned to the master switch during setup apply to all members of the Virtual Chassis)
  • Holds the active and master copy of the entire Virtual Chassis configuration
  • Shares Virtual Chassis configuration to his Back-up to maintain Redundancy

Backup:

This member acts as standby to the Master Routing Engine:

  • Serves as the Back-up (Standby) Routing Engine for the Virtual Chassis
  • Manages the entire Virtual Chassis
  • Synchronize with Master to make sure it has update Info shared by Master
  • Acquires mastership on Outage
  • Calculates and maintains the forwarding table and distributes it to the local CPU, and then to Packet Forwarding Engines (PFEs) in all member switches; Receives and transmits routing information
  • Shares Virtual chassis Configuration to Back-up & maintain Redundancy

Linecard:

These members contributes in multiplying Physical attributes:

  • Detects switch error conditions, such as an unplugged cable, on any interfaces that have been configured on it through the master switch and relays this information to the master switch
  • Receives updates about forwarding information from the master switch and programs these updates into the local PFE
  • Acquires Back-up’s task on outage

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

Verify that Virtual Chassis is in a healthy state, and troubleshoot if it is not

Below is a Troubleshooting Guide which verifies that a Virtual Chassis is in a healthy state and rescues 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.

In this article, the definition of a healthy Virtual Chassis is as follows:

  • A Virtual Chassis is considered healthy with a minimum of two members: Master and Backup, where one member will act as Master and the other member will be the Backup Routing Engine.
  • A Virtual Chassis can have a maximum of 10 members, where the rest of members have a role of Linecard.
  • All the members must have a status of Prsnt

Perform the following steps:


Step 1.  Run the command 'show virtual chassis status':

root@EX4200-VC# run 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 'Master' and a 'Backup' with the status Prsnt?

  • Yes - Continue to Step 2
  • No   - Jump to Step 4

Step 2.  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

Step 3. Since all the members are present, your Virtual Chassis is active. Sometimes administrators want a designated member to be the master. Is your expected master currently the master?


Step 4.  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

Step 5. [Member is Inactive] Run the command ‘show version’.

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

{master:1}[edit]
root@EX4200-VC# run 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 the Junos versions of all the Members the same?

  • Yes – If member is still isolated from the Virtual Chassis, collect the information in KB20569, and open a case with your technical support representative.
  • No – The member is Inactive because of a Junos version mismatch. To make the Inactive member active, reinstall Junos version to match the existing Virtual Chassis Master. For step by step instructions, refer to KB21133 - How to make inactive Virtual Chassis Member active.

Step 6.  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.


Step 7. [Member became NotPrsnt or is missing from the Virtual Chassis.] NotPrsnt means loss of Physical connectivity.

Console into the affected switch to troubleshoot the issue. Run the command ‘show virtual-chassis status’.

What is the Role of that particular member?
  • Isolated Switch reports Role as Linecard – Continue to Step 8
  • Isolated Switch reports Role as Master – Continue to Step 10

Step 8. [Isolated switch reports the Role as Linecard.] Re-active the Virtual Chassis to make that switch a stand-alone switch by running the following command:

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

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


Step 9.  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?

  • Yes – Restart at Step 1 to verify overall health.
  • No – If member is still isolated from the Virtual Chassis, collect the information in KB20569, and open a case with your technical support representative.

Step 10. [Isolated Switch reports Role as Master but not joining existing Virtual Chassis]

For example, in the output below, FPC 0 (Expected Back-Up: BR0208233776) Reports Role as Master but the member is not joining existing Virtual Chassis.

root@EX4200-VC# run 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 Master:

  1. Confirm 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),

  4. root@Ex4200-VC# load factory-default

    For more information, refer to KB11159 - Reverting to the Default Factory Configuration for the EX-series Switch .

  5. 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 still isolated, collect the information mentioned in KB20569, and open a case with your technical support representative.

Step 11. [Member became Unprvsnd (Not-provisioned)]

For example in the output below the expected Back-up (BR0208233776) became Not-Provisioned (Unprvsnd):
root@EX4200-VC# run 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      

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

Verify the Virtual Chassis Pre-Provisioning configuration is correct. In most of the cases, entering the serial number with the incorrect case is the issue; the Pre-Provision 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 the Technical Documentation:


Step 12. After correcting the pre-provisioning, run the command ‘show virtual-chassis status’.  Are any members still showing the status Unprvsnd?

  • No – Restart at Step 1 to verify the overall health
  • Yes – If still Unprvsnd, collect the information mentioned in KB20569, and open a case with your technical support representative





Additional Information Regarding Virtual Chassis Can be referred in below mentioned Link:
EX4200 and EX4500 Virtual Chassis


Related Links: