F5-CTS-LTM Practice Test 11 — 15 Questions

Question 1

An administrator wants to use an iRule to change the pool for an incoming request based on the URI. Which event should be used in the iRule?

Accepted Answer

HTTP_REQUEST. The HTTP_REQUEST event is the correct choice for inspecting HTTP traffic. It triggers as soon as the BIG-IP has parsed the HTTP request headers, allowing the iRule to evaluate the URI, cookies, or other headers. This is the optimal point to perform content-based switching, as it happens before the request is forwarded to a pool member, ensuring the load balancing decision is based on application-layer information.

Answer

CLIENT_ACCEPTED

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HTTP_RESPONSE

Answer

LB_SELECTED

Question 2

Refer to the exhibit. The LTM Specialist discovers that the HTTPS monitor is failing. The server logs indicate that the requests are reaching the web server, but the server is returning a 400 Bad Request error. What is the most likely cause?

Accepted Answer

The Host header in the send string does not match the server's expected virtual host.. The exhibit shows a manually defined send string that includes a Host header. A 400 Bad Request often indicates that the server does not recognize the Host header or the HTTP version specified in the request. In this configuration, the 'Host: example.com' header might be mismatched with the server's virtual host configuration, causing it to reject the request, which prevents the monitor from correctly identifying the server as healthy.

Answer

The BIG-IP is using the wrong SSL profile for the monitor.

Answer

The monitor is missing a 'Receive String' definition.

Answer

The monitor is using the wrong HTTP method.

Question 3

Which load balancing algorithm is best suited for a pool of servers where each server has different hardware specifications and processing capacities?

Accepted Answer

Ratio. The 'Ratio' load balancing method allows administrators to assign a weighting to each server based on its actual performance capability. In mixed-hardware environments, this prevents lower-spec servers from becoming overwhelmed while ensuring that more powerful servers handle a proportionately larger share of the traffic, thus maximizing the efficiency and reliability of the overall application delivery infrastructure.

Answer

Round Robin

Answer

Least Connections

Answer

Fastest

Question 4

Which profile type is used to optimize the delivery of HTTP traffic, such as enabling GZIP compression or caching?

Accepted Answer

HTTP profile. The HTTP profile is the engine for Layer 7 application optimization. It allows administrators to manipulate headers, compress content for faster delivery, and cache static assets. Because LTM is a full-proxy architecture, it can perform these optimizations on the fly, reducing the load on backend servers and decreasing the time to first byte, which is crucial for modern web performance metrics.

Answer

TCP profile

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Client SSL profile

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OneConnect profile

Question 5

What is the primary benefit of using SNAT (Source Network Address Translation) on a BIG-IP LTM system when communicating with backend pool members?

Accepted Answer

It ensures return traffic from pool members passes back through the BIG-IP.. SNAT simplifies network topology by ensuring that traffic returned from pool members to the BIG-IP always traverses the same device, even if the pool members are on different subnets or lack a default gateway pointing to the BIG-IP. This prevents asymmetric routing and ensures that the BIG-IP can correctly correlate return traffic with the original client request for session persistence and tracking.

Answer

It improves the security of the backend servers by encrypting data.

Answer

It increases the maximum number of concurrent client connections.

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It eliminates the need for health monitoring of pool members.

Question 6

Which load balancing algorithm would be best suited for a pool of servers where the servers have significantly different hardware specifications and processing capabilities?

Accepted Answer

Ratio (member). When servers in a pool are heterogeneous, using a simple round-robin approach causes faster servers to sit idle while slower servers become overloaded. The 'Ratio' algorithm allows administrators to assign a weight to each server, ensuring that higher-capacity servers receive a proportionally larger share of the traffic, which optimizes the overall system performance and prevents bottlenecking on the weaker backend hardware.

Answer

Round Robin

Answer

Least Connections

Answer

Fastest

Question 7

An administrator wants to ensure that all HTTP traffic is redirected to HTTPS. What is the most efficient way to perform this on a BIG-IP LTM?

Accepted Answer

Create a virtual server on port 80 with an iRule that performs a 301 redirect.. Creating a separate virtual server for port 80 that uses an iRule to issue an HTTP 301/302 redirect is the standard, cleanest method. This offloads the redirection logic from the main secure virtual server, keeping the configuration modular. It ensures that any insecure traffic is immediately directed to the secure listener, maintaining security compliance and simplifying the management of HTTP vs. HTTPS traffic.

Answer

Configure an HTTP profile on the virtual server to force SSL.

Answer

Modify the backend server settings to reject HTTP connections.

Answer

Use a SNAT pool to force all port 80 traffic to port 443.

Question 8

Which component of the BIG-IP system is responsible for managing the connection table and performing packet-level forwarding decisions?

Accepted Answer

Traffic Management Microkernel (TMM). The Traffic Management Microkernel (TMM) is the heart of the BIG-IP. It handles the data plane, including connection tracking, load balancing, and packet inspection. Understanding that TMM runs as a dedicated process separate from the management plane is essential for performance tuning and troubleshooting system-level issues, such as high CPU usage or packet loss during traffic spikes in high-throughput enterprise environments.

Answer

Configuration Utility (GUI)

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BigDB

Answer

MCPD

Question 9

An LTM Specialist needs to ensure that client traffic is distributed evenly across four backend servers, but some servers are more powerful than others. Which load balancing method should be chosen?

Accepted Answer

Ratio. Ratio load balancing is the appropriate method when server capacities differ. By assigning a higher ratio weight to the more powerful servers, the BIG-IP will send a proportionally larger amount of traffic to them. This ensures that the load is balanced relative to the processing power of each backend node, maximizing the performance of the overall application cluster and preventing smaller servers from being overwhelmed.

Answer

Round Robin

Answer

Least Connections

Answer

Observed

Question 10

Refer to the exhibit. What is the effect of the 'mask' setting in this source address persistence profile?

Accepted Answer

It groups clients from the same class C network for persistence.. The mask setting in a source address persistence profile allows the BIG-IP to group clients by subnet rather than individual IP address. By setting the mask to 255.255.255.0, the LTM treats all clients originating from the same /24 network as a single entity for persistence purposes. This is particularly useful in environments where many users share a gateway or proxy, preventing persistence table exhaustion.

Answer

It hides the individual client's IP from the backend server.

Answer

It limits the number of connections allowed from each subnet.

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It causes the LTM to ignore the source IP entirely.

Question 11

An LTM Specialist needs to configure a virtual server to handle both HTTP and HTTPS traffic on the same IP address. Which THREE steps are required to implement this? (Select THREE)

Accepted Answer

Create two virtual servers using the same virtual IP address.. To support both protocols, the BIG-IP needs a virtual server for each port (80 and 443). To handle them identically, they must share a pool. Additionally, the HTTPS virtual server requires an SSL profile to decrypt the traffic before it is load-balanced to the backend. This architecture allows the BIG-IP to manage both cleartext and encrypted sessions efficiently while centralizing management of the backend pool.

Answer

Configure a single virtual server with a wildcard port.

Answer

Disable the HTTP profile on the HTTPS virtual server.

Question 12

Which profile type is required to inspect and modify HTTP headers on a BIG-IP LTM virtual server?

Accepted Answer

HTTP Profile. An HTTP profile is required to enable the LTM to parse, understand, and manipulate HTTP traffic. Without an HTTP profile, the BIG-IP processes traffic at the TCP layer, making it impossible to see or alter application-level headers. This is a foundational concept for implementing security policies, X-Forwarded-For injection, or traffic routing based on HTTP hostnames or path information.

Answer

TCP Profile

Answer

FastL4 Profile

Answer

Client SSL Profile

Question 13

Which THREE features are provided by the BIG-IP LTM that assist in optimizing application performance?

Accepted Answer

TCP Express. BIG-IP LTM offers a suite of optimization tools. TCP Express, HTTP compression, and Caching are central to reducing latency and server load. These features work together to reduce the data sent over the wire and optimize how that data is transported, significantly improving the end-user experience for slow network connections and reducing backend resource consumption.

Answer

DNS Load Balancing

Answer

Firewall Rule Processing

Question 14

Which profile type must be attached to a virtual server to allow the BIG-IP to perform Layer 7 application inspection and modification?

Accepted Answer

HTTP Profile. An HTTP profile is the foundation for Layer 7 processing on the BIG-IP. It allows the system to parse HTTP requests and responses, which is necessary for features like cookie persistence, header insertion, and iRule-based traffic manipulation. Without an HTTP profile, the LTM acts only at the TCP layer, limiting its ability to understand or modify application-level data, which is vital for modern web application delivery.

Answer

TCP Profile

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Client SSL Profile

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Persistence Profile

Question 15

Which object acts as the primary configuration component that defines the destination IP address and service port for incoming client traffic?

Accepted Answer

Virtual Server. The Virtual Server is the fundamental LTM object that listens for client traffic. It acts as the gatekeeper, receiving packets on a defined IP and port, and then applying profiles, policies, and iRules before load balancing the traffic to a pool. Understanding the role of the Virtual Server is essential for all LTM operations, as it is the entry point for every application serviced by the BIG-IP device.

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Pool

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Node

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Profile