F5 SSL Certificate Upgrade

To handle expiring certificates on an F5 (BIG-IP) system, you can either renew or replace your certificates. Here’s a detailed guide on how you can manage this process:

Renewing Certificates

F5 does not provide a direct renewal option for certificates. Instead, you typically follow these steps:

A. Generate a Certificate Signing Request (CSR)

  1. Log in to the F5 BIG-IP Configuration utility.
  2. Navigate to System > File Management > SSL Certificate List.
  3. Click Create.
  4. Choose Certificate Signing Request (CSR) and click Next.
  5. Fill in the details for the CSR, such as Common Name (CN), Organization, Organizational Unit, etc.
  6. Click Finished to generate the CSR.

B. Submit the CSR to a Certificate Authority (CA)

  1. Take the generated CSR and submit it to your CA.
  2. The CA will issue a new certificate based on your CSR.

C. Import the New Certificate

  1. Once you receive the new Certificate from the CA, go back to the F5 BIG-IP Configuration utility.
  2. Navigate to System > File Management > SSL Certificate List.
  3. Click Import.
  4. Choose a certificate and fill out the required details.
  5. Upload the new certificate file you received from the CA.
  6. Ensure the new Certificate’s name matches the expiring Certificate’s name so you can overwrite it.

Uploading New Certificates

If you have a new certificate, you can upload it to the F5 and replace the expiring one.

A. Importing the New Certificate and Key

  1. Navigate to System > File Management > SSL Certificate List.
  2. Click Import.
  3. Choose Certificate.
  4. Give the new Certificate the same name as the old Certificate to overwrite it.
  5. Provide the certificate file and the key file.
  6. Click Import.

Best Practices

A. Overwriting Certificates

  • Overwrite Existing Certificate: When you import the new Certificate, if you give it the same name as the existing Certificate, it will overwrite the old one. This ensures you don’t have to update the SSL profiles for your virtual servers.

B. Testing New Certificates

  • Test in a Staging Environment: Before deploying the new Certificate to production, it’s wise to test it in a staging environment to ensure no issues.

C. Backup Existing Certificates

  • Backup Current Certificates: Before making any changes, back up the existing certificates and keys. This can be done by exporting them from the F5.
    1. Navigate to System > File Management > SSL Certificate List.
    2. Select the Certificate you want to back up.
    3. Click Export and save the Certificate and key.

D. Update Certificate Chain

  • Update Intermediate Certificates: If the CA has provided intermediate certificates, ensure you also upload these to the F5. You can do this in the same section where you import certificates.

Steps Summary:

  1. Generate CSR (if renewing).
  2. Submit CSR to CA and receive a new Certificate (if renewing).
  3. Import new Certificate and key using the same name as the expiring Certificate.
  4. Backup current certificates before making changes.
  5. Test the new Certificate in a staging environment.
  6. Update intermediate certificates if necessary.

By following these steps and best practices, you can seamlessly update your expiring certificates on your F5 without reconfiguring SSL profiles for your virtual servers.