F5CABR: F5 Certified Administrator, BIG-IP Recertification

The BIG-IP Configuration Utility runs on Apache (httpd) and uses PAM for authentication. PAM logs all authentication attempts — including GUI login attempts — to /var/log/secure, recording the username, timestamp, and whether the attempt succeeded or failed. This makes /var/log/secure the appropriate log to check to confirm whether a specific user tried to log in to the Configuration Utility.

The shopping cart emptying at checkout indicates that requests from the same client are being load-balanced to different pool members, causing loss of session-specific state stored on the originating server. Configuring a persistence profile on the virtual server ensures that all requests from a given client are consistently directed to the same pool member for the duration of the session, preserving cart data through checkout. Client SSL profiles handle TLS termination, HTTP profiles manage HTTP protocol behavior, and OneConnect profiles optimize backend TCP connection reuse — none of these provide client-to-server session affinity.

F5 BIG-IP tracks configuration changes per device in a device group and reports which device's configuration differs from the synchronized state. Because the change was made on the standby device, that device now holds the most recent, unsynchronized configuration, so the system's recommended action is to synchronize the standby member's configuration out to the rest of the device group, ensuring all members share the updated configuration.

SSH operates over TCP, and BIG-IP's HTTP and HTTPS monitors are designed to send HTTP-formatted requests and parse HTTP responses, which an SSH service does not provide, making them unsuitable. A UDP monitor would not properly test a TCP-based service like SSH. The TCP monitor is the appropriate choice because it establishes a TCP three-way handshake (and can optionally send/receive data) against the pool member's SSH port to confirm the service is up and accepting connections, which is the standard method for monitoring TCP-based services such as SSH when no protocol-specific monitor is configured.

On a BIG-IP system, the virtual server status icon in the Configuration Utility reflects both its administrative state and its availability, which is derived from the health of its pool members. A red diamond means the virtual server is enabled but currently unavailable — this occurs when the associated health monitors report that all pool members in the default pool are down, so the BIG-IP has no valid destination to forward traffic to. A disabled virtual server is shown with a different icon (a grey/black square), so that scenario would not produce a red diamond.