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Offline Subscription Architecture

If security policies or other considerations restrict network access to the Internet, you can update your CA Enterprise Log Manager environment through offline subscription. Offline subscription allows you to isolate some or all of your servers from the Internet while still keeping your CA Enterprise Log Manager environment up to date. Circumstances in which it is necessary to configure offline subscription include:

• No servers in your CA Enterprise Log Manager environment are permitted to internet access.
• Some servers in your network are allowed internet access, while others are not allowed even a connection to a server with internet access.

The only difference between online and offline subscription is how update files are delivered to the subscription proxy. In online subscription, the proxy contacts the CA Subscription Server over the Internet. In offline subscription, you download updates from a CA FTP site, then manually copy them to a CA Enterprise Log Manager server configured as an offline proxy.

The following diagram illustrates the offline subscription process. In this example, the entire CA Enterprise Log Manager environment is offline.

1. A system administrator downloads updates from a CA FTP site to a system that is allowed Internet or FTP access.
2. The system administrator manually copies the update files to an offline CA Enterprise Log Manager proxy. You can transfer the files using physical media such as a disk, or using scp, which is included with CA Enterprise Log Manager.
3. Updates then proceed exactly as in online subscription. The offline proxy self-installs the updates and pushes content updates to the management server.

   Note: You can allow the offline proxy to update itself as scheduled, it is good practice to perform a manual update on the offline proxy when you transfer new files. This practice ensures that the updates are available when subscription clients request them.

4. Clients of the offline proxy download the updates, according the schedule you set or when you perform a manual update.

   Note: Offline subscription clients always receive all updates that are manually installed on the offline proxy server. Subscription modules selected for an offline subscription client at the local level have no effect.

A subscription architecture can also be "mixed." For example, you can designate only one proxy as offline, while you designate others as online. The offline proxy and any clients assigned to it remain isolated from the Internet, while the rest of your CA Enterprise Log Manager environment receives updates through online subscription. Because of its complexity, a mixed architecture is not considered best practice. Carefully consider and plan your overall subscription strategy before implementing this architecture.

Important! In a mixed subscription environment, do not include offline proxies in the proxy list for any online subscription client. If you do, the online subscription client automatically receives all updates that are manually installed, instead of the modules you selected globally for your CA Enterprise Log Manager environment or locally for that client.

More information

How to Plan Subscription Updates

Subscription Architecture