When attempting to add the certificate to the CA Certificate store an error message pops up. Unfortunately there is no clear easy way to tell from the message where the certificate already exists.
The error message will show the following text:
% Certificate Authority certificate has been imported already
In order to identify where the existing certificate is follow the steps below.
1. Open the certificate you would like to add in a notpad file and copy a portion of the body of the certificate you are trying to add
2. On the ProxySG GUI, navigate to Configuration -> General -> Archive. Select the tab "archive configuration" and from the "view current configuration" drop down select Configuration - Expanded. Click 'View file' and save the output that appears on a new tab to a .txt file.
3. Open the .txt file created in step 2 and search for the string of text copied in step 1. Above the ----- BEGIN CERTIFICATE ---- text you will find the name the cert is titled within the CA Certificates list in the GUI.