F5CAB3 Exam Dumps - BIG-IP Administration Data Plane Configuration (F5CAB3) exam

URI-based traffic steering requires inspection of the HTTP request. BIG-IP processes HTTP headers and URIs in the HTTP_REQUEST event. Pool member selection based on URI must occur before the request is sent to the server, making HTTP_REQUEST the correct event.

DNS traffic is primarily transported using UDP port 53. In the exhibit, the Virtual Server is configured with the Protocol set to TCP, which prevents standard DNS queries from being processed correctly. BIG-IP Virtual Servers must be configured with the correct Layer 4 protocol to match the application traffic they are handling.

According to the BIG-IP Administration: Data Plane Configuration documentation:

The Protocol setting on a Virtual Server defines whether traffic is processed as TCP, UDP, or another supported transport protocol.

Standard DNS queries and responses use UDP, while TCP is only required for DNS zone transfers (AXFR) or exceptionally large responses.

When a DNS Virtual Server is incorrectly configured with TCP, UDP-based DNS queries are dropped, causing all requests to fail.

Why the other options are incorrect:

A. Protocol profile (Client) to DNS_OPTIMIZEDA DNS profile enhances DNS functionality but does not correct an incorrect transport protocol configuration.

B. Type to Performance (HTTP)Performance (HTTP) Virtual Servers are designed for HTTP traffic and are not suitable for DNS services.

C. Source Address to 192.168.10.0/24The existing source IPs already fall within the allowed range, so this setting does not address the failure.

Correct Resolution:

Changing the Protocol to UDP aligns the Virtual Server with standard DNS transport requirements, allowing DNS queries to be successfully processed and load-balanced.

A red diamond indicates that the Virtual Server is enabled but unavailable, typically due to all pool members being down.

SSH is a Layer 4 TCP-based protocol that operates on TCP port 22 and does not use HTTP in any capacity. In the exhibit, the Virtual Server is configured with an HTTP Profile applied, which is inappropriate for SSH traffic and causes connection failures.

According to the BIG-IP Administration: Data Plane Configuration documentation:

An HTTP profile must only be applied to Virtual Servers handling HTTP or HTTPS traffic.

When an HTTP profile is attached, BIG-IP expects HTTP headers and attempts to parse application-layer data.

Non-HTTP protocols such as SSH, FTP (control), SMTP, and other raw TCP services will fail if an HTTP profile is enabled.

Why the other options are incorrect:

A. Set Protocol to UDPSSH uses TCP, not UDP. Changing the protocol would break SSH entirely.

B. Set Source Address to 10.1.1.2The source address setting controls client access restrictions and is unrelated to protocol parsing issues.

C. Set Destination Address/Mask to 0.0.0.0/0The destination address is already valid for a specific SSH service and does not impact protocol handling.

Correct Resolution:

The BIG-IP Administrator should remove the HTTP Profile (set it to None) so the Virtual Server functions as a pure Layer 4 TCP service, allowing SSH connections to pass through successfully.

Standard DNS queries use UDP. Configuring the Virtual Server for TCP causes DNS traffic to fail.