Portal access allows end users access to internal web applications with a web browser from outside the network. With portal access, the BIG-IP Access Policy Manager communicates with back-end servers, and rewrites links in application web pages so that further requests from the client browser are directed back to the Access Policy Manager server. With portal access, the client computer requires no specialized client software other than a web browser.

Portal access provides clients with secure access to internal web servers, such as Microsoft OutlookWeb Access (OWA), Microsoft SharePoint, and IBM Domino Web Access. Using portal access functionality, you can also provide access to most web-based applications and internal web servers.

Portal access differs from network access, which provides direct access from the client to the internal network. Network access does not manipulate or analyze the content being passed between the client and the internal network. The portal access configuration gives the administrator both refined control over the applications that a user can access through Access Policy Manager, and content inspection for the application data. The other advantage of portal access is security. Even if a workstation might not meet requirements for security for full network access, such a workstation can be passed by the access policy to certain required web applications, without allowing full network access. In a portal access policy, the client computer itself never communicates directly with the end-point application. That means that all communication is inspected at a very high level, and any attacks originating on the client computer fail because the attack cannot navigate through the links that have been rewritten by the portal access engine.