replace n7k supervior module

[Herman2018]

hi, we have two n7k ,each is with single supervisor module (sup-e2) only. some vdc are created on each n7k: vdc-a, vdc-b and vdc-c.

The vdc-a on both n7k are configured as one vpc domain. Now one n7k supervisor module goes wrong, need to replace. What is the correct procedure so that won't cause any vpc issue. Can someone pleas advise, thanks in advance. My temp plan is shown as below.

1. save all vdc and admin config 

2. power off the n7k as only single supervisor module on it

3. replace supervisor module with new one

4. console in to new n7k supervisor module to setup mgmt ip

5. upload the admin config 

6. check all the vdcs status and upload vdcs config : vdc-a, vdc-b, vdc-c 

7. verify all vdc config and save the config

8. test network 

is the steps above correct? will it cause any issue to another n7k and the rest network? 

[AshSe · Accepted solution]

Hello @Herman2018 

hi, we have two n7k ,each is with single supervisor module (sup-e2) only. some vdc are created on each n7k: vdc-a, vdc-b and vdc-c.

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Is it "some" or "same"?

Now answer to your main question:

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The vdc-a on both n7k are configured as one vpc domain. Now one n7k supervisor module goes wrong, need to replace. What is the correct procedure so that won't cause any vpc issue. Can someone pleas advise, thanks in advance.

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Your proposed steps for replacing the failed supervisor module in a Cisco Nexus 7000 switch with a single supervisor module are generally correct, but there are a few important considerations and refinements to ensure minimal disruption to the vPC domain and the rest of the network. Let me walk you through the process and address potential issues.

Key Considerations:

1. vPC Peer Switch Behavior:

   • In a vPC setup, when one switch in the vPC domain goes offline (e.g., due to a supervisor failure or replacement), the other switch continues to operate as the active vPC peer. However, during this time, the network is running in a degraded state with no redundancy.
   • It is critical to ensure that the remaining active vPC peer (the other Nexus 7000) is stable and functioning properly before proceeding with the replacement.

2. Impact on the Network:

   • When the failed Nexus 7000 is powered off, the vPC domain will lose one of its peers. This can cause a temporary loss of redundancy, but traffic should continue to flow through the remaining active vPC peer.
   • Proper configuration and synchronization of the vPC peer link and peer-keepalive link are essential to avoid issues when the replaced switch comes back online.

3. Configuration Restoration:

   • Since the Nexus 7000 has multiple VDCs, you need to ensure that the configuration for the admin VDC and all other VDCs (vdc-a, vdc-b, vdc-c) is backed up and restored correctly.
   • The vPC domain configuration (e.g., vPC peer link, vPC keepalive, and vPC member ports) must be restored exactly as it was to avoid any disruption when the replaced switch rejoins the vPC domain.

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Refined Procedure for Replacing the Supervisor Module:

Step 1: Backup Configurations

• Save the configuration for the admin VDC and all other VDCs (vdc-a, vdc-b, vdc-c) on the failed Nexus 7000.
  • Use the copy running-config startup-config command to ensure the current configuration is saved.
  • Export the configuration files to an external server (e.g., TFTP or SCP) for safekeeping:

    copy running-config tftp://<server-ip>/<filename>
    

• Verify that the vPC configuration is synchronized between the two Nexus 7000 switches using the show vpc command on the remaining active switch.

Step 2: Power Off the Failed Nexus 7000

• Since the switch has only a single supervisor module, you must power it off to replace the module. Notify stakeholders about the temporary loss of redundancy in the vPC domain.

Step 3: Replace the Supervisor Module

• Physically replace the failed supervisor module with the new one.

Step 4: Power On the Nexus 7000

• Power on the switch with the new supervisor module installed.
• Connect to the console of the new supervisor module to perform the initial setup.

Step 5: Restore the Admin VDC Configuration

• Configure the management IP address for the admin VDC.
• Upload the saved admin VDC configuration file to the switch:

  copy tftp://<server-ip>/<admin-config-file> running-config
  

• Verify the admin VDC configuration.

Step 6: Restore VDC Configurations

• Check the status of all VDCs (vdc-a, vdc-b, vdc-c) using the show vdc command.
• Restore the configuration for each VDC from the saved configuration files:

  switchto vdc <vdc-name>
  copy tftp://<server-ip>/<vdc-config-file> running-config
  

• Verify the configuration for each VDC.

Step 7: Verify vPC Configuration

• Ensure that the vPC peer link and peer-keepalive link are configured correctly and are operational.
• Use the show vpc command to verify the vPC status and synchronization between the two Nexus 7000 switches.
• Check for any vPC consistency errors and resolve them if necessary.

Step 8: Save the Configuration

• Save the configuration for the admin VDC and all other VDCs:

  copy running-config startup-config
  

Step 9: Test the Network

• Verify that all VDCs are functioning as expected.
• Test the vPC domain to ensure that traffic is flowing correctly and redundancy has been restored.
• Check the status of all interfaces, VLANs, and routing protocols.

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Potential Issues and How to Avoid Them:

1. vPC Role Changes:

   • When the failed Nexus 7000 is powered off, the remaining switch in the vPC domain will take over as the primary or secondary vPC peer (depending on the original configuration).
   • When the replaced switch comes back online, it must rejoin the vPC domain without causing a role conflict or traffic disruption. Ensure that the vPC role priority is configured correctly on both switches.

2. vPC Consistency Check Failures:

   • If the vPC configuration is not restored correctly, you may encounter consistency check failures, which can cause vPC member ports to go into a suspended state.
   • Use the show vpc consistency-parameters command to verify that the vPC configuration is consistent between the two switches.

3. Loss of Configuration:

   • If the configuration is not backed up properly, you may lose critical settings for the admin VDC or other VDCs. Double-check that all configurations are saved and exported before proceeding.

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Final Thoughts:

Your proposed steps are mostly correct, but I recommend adding the following refinements:

• Explicitly verify the vPC configuration and consistency before and after the replacement.
• Ensure that the configuration for all VDCs is backed up and restored correctly.
• Test the network thoroughly after the replacement to confirm that redundancy and functionality have been restored.

By following these steps, you should be able to replace the failed supervisor module without causing any major issues to the vPC domain or the rest of the network.

Hope This Helps!!!

AshSe

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[Herman2018]

thanks @AshSe a lot for your kind advice!