1.0 Problem Analysis

This document addresses the procedural requirements for correctly clearing the configuration and dismantling a Virtual Switching System (VSS) pair composed of two Cisco Catalyst 4507R+E chassis, reverting them to two independent, standalone switches with a factory-default configuration.

The initial technical problem presented involves a scenario where standard configuration removal commands (write erase followed by reload) were executed on the active VSS switch. This action successfully removed the startup configuration file, but upon reboot, the system retained its VSS identity. The chassis booted into VSS mode, with one acting as the active virtual switch and the other as the hot-standby, indicated by console prompts such as Switch-1-stby-rp> and Switch-2-stby-rp>.

The core issue stems from a misunderstanding of how VSS mode is configured and maintained on the Catalyst 4500 platform. The VSS operational mode is a persistent system-level setting stored outside of the startup-config file in NVRAM. Therefore, simply erasing the startup configuration does not instruct the switches to abandon their VSS roles. The system boots without a configuration but still attempts to form a VSS domain based on this persistent setting, leading to an improperly configured state. The correct procedure requires a specific command to formally convert the system from VSS mode back to standalone mode.

2.0 Pre-Requisite Actions and Best Practices

Prior to initiating the VSS-to-standalone conversion process, adherence to the following best practices is mandatory to ensure a controlled transition and mitigate operational risk:

• Schedule a Maintenance Window: This procedure will cause a complete network outage for all devices connected to the VSS pair as both chassis will reboot.
• Configuration Backup: Perform a complete backup of the VSS running configuration. Use the command show running-config and save the output to a secure external location (e.g., TFTP, SCP server). This backup is critical for reference or potential rollback scenarios.
• Physical Console Access: Establish and verify direct console access to both physical Catalyst 4507R+E chassis. After the conversion, the single management point of the VSS will be dissolved, and each switch must be configured and verified independently.

3.0 Recommended Procedure for VSS Decommissioning

The following step-by-step procedure provides the official, Cisco-validated method for converting a VSS pair to two standalone switches.

Step 1: Initiate the Conversion from the Active Switch
Access the command-line interface (CLI) of the VSS active switch via SSH, Telnet, or the active supervisor’s console port.

Step 2: Enter Global Configuration Mode
From the privileged EXEC mode, enter global configuration mode:

Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)#

Step 3: Execute the Standalone Mode Conversion Command
This is the most critical step. The switch convert mode standalone command gracefully dismantles the VSS domain.

Switch(config)# switch convert mode standalone

Step 4: Confirm the System Reload
The system will display a warning message indicating that this action will cause both switches in the VSS to reload and will save a backup of the VSS configuration. You must confirm to proceed.

This command will convert the VSS to a standalone switch and
will reload BOTH switches.
The VSS configuration will be backed up to "flash:vss_config".
Do you want to proceed? [yes/no]: yes

Upon confirmation, both chassis will begin their reload sequence.

Step 5: Post-Conversion Verification
After the switches have rebooted, connect to the console port of each physical chassis individually. They will now be operating as two separate, independent switches. The original VSS configuration (interfaces, VLANs, etc.) will be present on what was formerly the active switch, while the former standby switch will have a minimal configuration. Verify their standalone status using the show switch command. The command show switch virtual will no longer be valid.

4.0 Final Configuration Cleanup

To achieve the original objective of a completely cleared, factory-default configuration on both switches, perform the following steps on each switch independently after verifying they are in standalone mode.

Step 1: Erase the Startup Configuration
On the console of the first switch, execute the write erase command to remove the startup configuration file.

Switch-1# write erase
Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]
[OK]
Erase of nvram: complete.
Switch-1#

Step 2: Reload the Switch
Reload the switch to boot with a clean, default configuration.

Switch-1# reload

Step 3: Repeat for the Second Switch
Connect to the console of the second switch and repeat steps 1 and 2.

Upon completion of this entire procedure, both Catalyst 4507R+E chassis will be operating as independent, standalone switches with a factory-default configuration, ready for new provisioning.