F5-CTS-LTM Practice Test 10 — 10 Questions

Question 1

Which THREE conditions must be met for Connection Mirroring to function correctly between two BIG-IP devices in a high-availability pair?

Accepted Answer

The devices must be members of a Sync-Failover device group.. Connection Mirroring requires specific synchronization prerequisites. The devices must be in a device group, a mirror IP address must be defined for the VLANs, and the virtual server must have mirroring explicitly enabled. This ensures that the state information of TCP and persistence sessions is replicated, allowing for hitless failover where clients do not have to re-establish their connections upon a standby-to-active transition.

Answer

The virtual server must use a 'Fast L4' profile.

Answer

The pool members must be in the same subnet as the BIG-IP.

Question 2

What is the primary function of a OneConnect profile on a BIG-IP Virtual Server?

Accepted Answer

It enables TCP connection pooling to backend servers.. OneConnect enables TCP connection pooling between the BIG-IP and backend servers. By keeping connections open, it reduces the overhead of the three-way handshake for every request, which significantly improves performance, especially for HTTP/1.1 traffic. This is a critical configuration for high-traffic environments where connection setup latency can become a bottleneck, allowing the BIG-IP to maximize backend server resource utilization by reusing established connections for multiple client requests.

Answer

It encrypts traffic between the BIG-IP and the server.

Answer

It forces clients to use a single persistent connection.

Answer

It compresses HTTP traffic before sending to the server.

Question 3

Which component of the BIG-IP LTM system is responsible for performing health checks on backend servers to determine if they are capable of accepting new connections?

Accepted Answer

The Health Monitor. Health monitors are the LTM component used to periodically verify the status of pool members. By sending specific requests—such as ICMP, TCP, or HTTP—the LTM determines if a server is healthy. If a monitor fails, the LTM marks the member as 'down' and stops sending traffic to it, which is essential for maintaining application availability and preventing users from hitting broken services.

Answer

The Persistence Profile

Answer

The SNAT Automap

Answer

The Virtual Server

Question 4

Refer to the exhibit. What is the primary purpose of enabling 'insert-xforwarded-for' in the HTTP profile?

Accepted Answer

To allow the server to identify the original client's IP address.. When the BIG-IP acts as a proxy, the backend servers see the BIG-IP's IP address as the source of all traffic. By inserting the X-Forwarded-For header, the BIG-IP includes the original client's IP address in the HTTP request. This allows backend applications to log the true client IP for auditing, security analysis, and personalization, which would otherwise be lost due to the LTM's source IP translation.

Answer

To hide the backend server's IP address from the client.

Answer

To increase the throughput of HTTP requests.

Answer

To bypass the need for an SSL profile.

Question 5

Which load balancing method is best suited for a pool where servers have significantly different processing capabilities and hardware specifications?

Accepted Answer

Ratio (member). The 'Ratio' load balancing method allows administrators to assign weights to pool members, directing more traffic to more powerful servers. In heterogeneous environments, using a static method like Round Robin would overwhelm weaker servers while underutilizing stronger ones. Ratio-based load balancing provides the necessary control to optimize performance and server utilization based on the actual capacity of each individual backend node in the cluster.

Answer

Round Robin

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Least Connections

Answer

Observed

Question 6

An LTM Specialist is troubleshooting an issue where client browsers are receiving errors when connecting via HTTPS. The virtual server is working fine for plain HTTP. Which THREE of the following could be the cause? (Choose three)

Accepted Answer

The Client SSL profile is using an expired certificate.. HTTPS issues usually stem from certificate, profile, or protocol mismatch problems. An expired certificate, a missing intermediate certificate in the chain, or an incompatible SSL profile will break the TLS handshake. These issues are common in LTM deployments and must be systematically ruled out by checking the BIG-IP logs, certificate stores, and profile settings to ensure the handshake can complete successfully between the client and the BIG-IP.

Answer

The virtual server is missing a Server SSL profile.

Answer

The virtual server is listening on the wrong port.

Question 7

An administrator needs to monitor the health of a web service that uses an unconventional port and requires a specific string to be returned in the response. Which monitor type should be used?

Accepted Answer

An HTTP monitor with the 'Send String' and 'Receive String' configured.. The HTTP monitor is designed for checking web services. By specifying the port and the 'Receive String' field, the administrator can verify that the server is not only listening but also returning the expected content. This is essential for detecting 'grey failure' scenarios where a server responds to a TCP connection but serves an error page or an incomplete application response.

Answer

A standard TCP monitor with the port defined in the monitor configuration.

Answer

An ICMP monitor added to the pool member's health monitor list.

Answer

An external monitor script that performs a shell command to check the service.

Question 8

An administrator wants to ensure that a specific server in a pool receives more traffic than others due to its higher hardware capacity. Which load balancing method should be used?

Accepted Answer

Ratio. The 'Ratio' load balancing method allows an administrator to assign a weight to each pool member. A server with a higher ratio will receive a proportionally larger number of connections compared to servers with lower ratios. This is the correct method for load balancing in heterogeneous environments where hardware performance varies, ensuring that more capable servers handle a larger share of the overall traffic load.

Answer

Round Robin

Answer

Least Connections

Answer

Fastest

Question 9

Refer to the exhibit. The virtual server is showing client-side traffic but no server-side traffic. What is the most likely reason?

Accepted Answer

All pool members are currently marked down by health monitors.. When a virtual server shows incoming client traffic but zero outgoing server traffic, it usually indicates that the BIG-IP cannot establish a connection to the pool members. This is often caused by a pool being empty, all members being marked down by health monitors, or a routing issue preventing the BIG-IP from reaching the backend servers. The lack of server-side connections confirms the BIG-IP is not successfully forwarding requests.

Answer

The virtual server is configured with an incorrect destination IP address.

Answer

The client is sending traffic that does not match the HTTP profile.

Answer

The BIG-IP is configured with an incorrect default gateway.

Question 10

When configuring a custom monitor, what happens if the 'Time Until Up' is set to 0?

Accepted Answer

The monitor marks the node as up after the first success.. Setting 'Time Until Up' to zero disables the 'slow start' or 'delayed up' feature of the health monitor. The member is marked 'Up' immediately upon the first successful probe. This is crucial for environments where rapid recovery is required, but it can lead to 'flapping' if the server is unstable. Understanding monitor timing is vital for ensuring high availability without introducing unnecessary instability in the backend pool infrastructure.

Answer

The monitor will never mark the node as up.

Answer

The monitor will fail to send any probes.

Answer

The monitor will use the default system timeout.