Authentic F5 Certification Exam F5CAB3 Questions Answers

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.

According to the provided exhibit, the " SSL Profile (Client) " section in the Virtual Server configuration is empty. For a BIG-IP system to process HTTPS traffic, it must act as an SSL/TLS endpoint. This process, known as SSL Termination or SSL Offload, requires the assignment of a Client SSL Profile to the Virtual Server. Without this profile, the BIG-IP does not have the necessary certificate and private key information to perform the SSL handshake with the client ' s browser. Consequently, when a user attempts to connect via HTTPS, the TCP connection may establish, but the SSL handshake will fail because the BIG-IP will not know how to decrypt the incoming encrypted packets.

A Client SSL profile defines the ciphers, certificates, and keys that the BIG-IP uses to communicate securely with the client. In a standard HTTPS deployment, the BIG-IP decrypts the traffic and can then send it to the backend pool members either as plain text (header insertion/manipulation) or re-encrypt it using a Server SSL profile. While a Server SSL profile (Option C) is needed if the backend servers themselves require HTTPS, the initial failure for a user reaching a Virtual Server is almost always the lack of a Client SSL profile to terminate the user ' s connection. Changing the Service Port to HTTP (Option D) would be incorrect because the goal is to handle HTTPS traffic (typically port 443). Assigning the " clientssl " or a custom client-side profile from the " Available " list to the " Selected " list in the GUI is the mandatory step to make the Virtual Server operational for secure web traffic.

To determine if an iRule is influencing traffic for a specific Virtual Server, the administrator must verify the association between the Virtual Server object and any applied scripts. In the BIG-IP Configuration Utility (GUI), this association is found under the Resources tab of the specific Virtual Server. While there is an " iRules " sub-menu under Local Traffic, checking the Virtual Server ' s Resources tab is the definitive way to see which specific rules are currently active and in what order they are being processed for that particular traffic flow.

From the Command Line Interface (CLI), the tmsh list /ltm virtual < virtual_server > command provides a full text-based output of the virtual server ' s configuration. If iRules are applied, they will appear within a " rules { ... } " block in the command output. This is more effective than Option A, which only lists the contents of the iRule itself but does not show if or where it is applied. Option C is a common misconception; while some versions of the GUI have reorganized menus, the standard location for managing the association of profiles, policies, and iRules to a Virtual Server remains the " Resources " section. By identifying the applied iRule, an administrator can then review the script logic—often containing commands like pool or node—to see if it is overriding the default pool selection based on specific HTTP headers, URI paths, or client IP addresses.