F5 F5CAB5 Practice Test Questions Answers

To successfully performSSL offload and re-encryptionon a BIG-IP system, the virtual server must be configured withboth a Client SSL profile and a Server SSL profile. The Client SSL profile enables BIG-IP to decrypt inbound HTTPS traffic from clients, while the Server SSL profile is required tore-encrypt traffic before forwarding it to the pool members.

From the exhibit, the virtual server has aClient SSL profile configured, which allows BIG-IP to accept HTTPS connections from clients. However, there isno Server SSL profile attached, meaning BIG-IP attempts to sendunencrypted HTTP trafficto pool members listening on HTTPS (port 443). This protocol mismatch causes the server-side SSL handshake to fail, resulting in users being unable to connect to the application.

This behavior is well documented in BIG-IP SSL troubleshooting guides: when backend servers expect HTTPS, a Server SSL profile is mandatory to establish a secure connection from BIG-IP to the pool members.

The other options are incorrect:

Removing the Client SSL profile (Option A) would break client-side HTTPS.

The server-side TCP profile (Option B) is unrelated to SSL encryption.

Forward Proxy (Option C) is only used for outbound SSL inspection scenarios.

Therefore, configuring anSSL Profile (Server)is the correct and required solution.

The pool member is markedDOWNbecause it is monitored bymultiple health monitors, specifically anHTTPmonitor and anHTTP/2monitor. The status message clearly shows that theHTTP monitor is UP, while theHTTP/2 monitor is DOWN. In BIG-IP, when multiple monitors are assigned to a pool member, the default behavior isAND logic, meaningall assigned monitors must succeedfor the pool member to be considered healthy.

In this scenario, the server is responding successfully to standard HTTP (likely HTTP/1.1) requests but does not support or respond correctly to HTTP/2 requests. As a result, the HTTP/2 monitor fails, which causes the overall monitor status to beDOWN, even though HTTP traffic itself is working.

This behavior is expected and documented in BIG-IP monitoring logic. Unless the monitor rule is explicitly changed to“at least one of”, a single failing monitor will mark the pool member down. Therefore, the correct conclusion is that the pool member isonly serving HTTP traffic, not HTTP/2.

The resolution would be to either remove the HTTP/2 monitor, correct the application to support HTTP/2, or adjust the monitor rule to match the intended health-check logic.

Comprehensive and Detailed Explanation From BIG-IP Administration Support and Troubleshooting documents: Monitoring resource utilization is essential for maintaining system stability. If the root (/) file system reaches 100% capacity, the BIG-IP may become unresponsive, fail to save configuration changes, or experience daemon crashes83. When the / partition is full, the immediate troubleshooting step is to identify large or unnecessary files—such as old log files, core dumps, or temporary installer files—located specifically within that file system84. In the provided exhibit, /dev/md4 is explicitly listed at 100% usage for the / mount point85. Checking other partitions like /usr (which is at 82% in the exhibit) would not resolve the immediate "Full" status of the root directory86. Administrators often use the du (disk usage) command via the CLI to find the problematic files. Managing disk space is a proactive task; however, when utilization hits 100%, it becomes a reactive troubleshooting emergency that must be resolved to restore the management plane's functionality.

When a virtual server's traffic flow is disrupted only during failover events and takes several minutes to stabilize, the issue is typically related to the ARP cache on upstream network devices47. By default, each BIG-IP in an HA pair uses its own unique hardware MAC address for traffic4848. When a failover occurs, the new active device takes over the floating IP addresses, but the upstream switch may still have the MAC address of the old device cached4949. Traffic fails until the switch's ARP entry is updated. "MAC Masquerade" is a troubleshooting feature that assigns a shared, virtual MAC address to the floating traffic group. Regardless of which BIG-IP is currently active, it will use this masqueraded MAC address for all traffic related to that group52. Because the MAC address seen by the network never changes during a failover, the upstream devices do not need to relearn ARP entries, resulting in an instantaneous transition and eliminating the performance drop reported by users

The exhibit shows the virtual serverapplication_vswith a status indicating it isoffline but enabled. In BIG-IP terminology, this status means the virtual server itself is administratively enabled, but it is unable to pass traffic becauseno usable pool members are available.

Two common and documented causes for this condition are:

Pool member(s) administratively disabled (Option A):When all pool members are administratively disabled, BIG-IP removes them from load-balancing decisions. Even though the virtual server remains enabled, it has no available pool members to send traffic to, resulting in an offline status.

Node(s) administratively disabled (Option C):Pool members inherit the status of their parent nodes. If a node is administratively disabled, all associated pool members are also marked unavailable. This condition causes the virtual server to show as offline, even though the virtual server configuration itself is correct.

The other options are incorrect:

Forced offline pool members (Option B)result in a different operational intent and are explicitly set for maintenance scenarios.

Virtual server administratively disabled (Option D)would show the virtual server as disabled, not enabled/offline.

This behavior is consistent with BIG-IP traffic management logic and is commonly verified by reviewingpool and node availability stateswhen diagnosing virtual server availability issues.