APC NMC/PDU Web UI Access Denied (Expired SSL)

Issue

An expired SSL certificate on the APC Network Management Card (NMC) or Rack PDU causes HTTPS communication to break. When attempting to access the Web UI, the browser displays a “Page Not Found” or “Connection Reset” error.

Resolution

Step 1: Gain Management Access

If HTTP access is already enabled on the device, skip to Step 2. If HTTP is disabled, you must use the Command Line Interface (CLI):

  1. SSH into the appliance using your deployment credentials (e.g., username apc).
  2. Run the following command to temporarily enable HTTP access:
    web -h enable
  3. Reboot the NMC to apply the changes by typing:
    reboot

Step 2: Clear the Expired Certificate via Web UI

  1. Open a web browser and navigate to the appliance using HTTP
  2. Log in and navigate to: Configuration > Network > Web > SSL Certificate
  3. Change the configuration radio button to Remove and click Apply. (Note: This deletes the expired certificate and forces the device to automatically generate a fresh self-signed certificate upon the next reboot).

Step 3: Restore Secure Settings & Reboot

  1. Navigate to: Configuration > Network > Web > Access
  2. Disable HTTP to maintain environment security, ensuring HTTPS remains enabled. Click Apply.
  3. To finalize and save all changes, execute a final reboot by navigating to: Control > Network > Reset/Reboot

Note: If you are dealing with older NMC2 firmware (pre-v7.0.4), the newly generated self-signed certificate will expire again in 1 year. To prevent this cycle, consider upgrading the NMC firmware to the latest stable release branch, which issues long-life certificates.

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