F5-CTS-LTM Practice Test 6 — 10 Questions

Question 1

You are managing an LTM and notice that some traffic is not being load-balanced as expected. You see that an iRule is applied to the virtual server. What is the most likely reason the iRule is overriding the load-balancing method?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The iRule explicitly selects a pool or node.. iRules are processed before standard load balancing in the BIG-IP pipeline. When an iRule contains commands like 'pool' or 'node', it can explicitly select a destination server, effectively bypassing the configured load-balancing algorithm. This is a common point of confusion for administrators, as the iRule logic can override the expected behavior of the pool's load-balancing method.

Answer

The iRule is only triggered when the pool is empty.

Answer

The load-balancing method is incompatible with iRules.

Answer

The iRule is disabled by the current license.

Question 2

Refer to the exhibit. What happens to the user session if the 'my_app_cookie' is not present in the initial client request?

Accepted Answer

The BIG-IP inserts a cookie in the response.. With the 'insert' method, the BIG-IP will inject a persistence cookie into the HTTP response header sent to the client. The client browser will then store this cookie and include it in all subsequent requests. This allows the BIG-IP to correctly route the user back to the same backend server on future requests without the backend application needing to handle the session tracking logic itself.

Answer

The request is dropped by the LTM.

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The LTM forces a redirect to the login page.

Answer

Persistence is permanently disabled for that session.

Question 3

Refer to the exhibit. An administrator checks the status of 'web_pool' and observes the output shown. What is the most likely cause for the pool being offline?

Accepted Answer

The health monitors assigned to the pool members are failing.. The output indicates that the pool is offline because all members are unavailable. In LTM, a pool's availability status is determined by the health of its members. When all monitors fail or the members are manually disabled, the pool enters an offline state. This is a fundamental concept for troubleshooting service outages, as it immediately identifies that the issue lies with the backend servers rather than the VIP.

Answer

The Virtual Server associated with the pool is disabled.

Answer

The load balancing method is set to Round Robin.

Answer

The license for the LTM module has expired.

Question 4

Which health monitor type should be used when you need to verify that a web server is not only responding to TCP connections but also returning the correct content for a specific page?

Accepted Answer

HTTP monitor with 'send' and 'receive' strings.. An HTTP or HTTPS monitor is required to validate application-layer content. Simple TCP monitors only verify that the port is open and listening; they cannot confirm if the web server is actually serving pages or returning errors. By configuring an HTTP monitor with a 'send' and 'receive' string, the BIG-IP can ensure the application is functioning correctly, not just the network stack.

Answer

TCP Half-Open monitor.

Answer

ICMP monitor.

Answer

SNMP DCA monitor.

Question 5

An administrator needs to ensure that client SSL traffic is terminated at the BIG-IP LTM while maintaining persistence based on a specific session cookie. Which profile combination correctly enables this functionality?

Accepted Answer

Client SSL profile and Cookie Persistence profile. To terminate SSL, a Client SSL profile must be assigned to the Virtual Server. To persist based on a cookie, a Cookie Persistence profile must be enabled. This combination is standard for web applications requiring secure transport and session stickiness. Understanding this architecture is vital because the LTM must decrypt traffic to inspect and insert the persistence cookie, allowing the BIG-IP to make intelligent load-balancing decisions based on application-layer data.

Answer

Server SSL profile and Source Address Affinity profile

Answer

Client SSL profile and Source Address Affinity profile

Answer

Server SSL profile and Cookie Persistence profile

Question 6

A virtual server is configured with a 'Least Connections' load balancing method. Under what specific scenario would this method be more effective than 'Round Robin'?

Accepted Answer

When backend servers process requests with varying execution times.. Least Connections is ideal when backend servers handle requests of varying complexity or duration. Because it tracks active connections, it avoids sending new requests to a server that is already busy, whereas Round Robin blindly rotates through all servers. This ensures better distribution of load in environments where some requests take significantly longer to process, preventing any single server from becoming a bottleneck during traffic spikes.

Answer

When all backend servers are identical in hardware specifications.

Answer

When the application consists of simple, static web pages.

Answer

When the virtual server is configured with a high persistence timeout.

Question 7

When configuring a BIG-IP LTM, what is the significance of the 'Service Down Action' setting on a virtual server?

Accepted Answer

It defines how the BIG-IP handles traffic when no pool members are available.. The 'Service Down Action' determines the behavior of the BIG-IP when all pool members are marked as 'Down' by the health monitor. Options include rejecting the connection, dropping it, or sending it to a fallback host. This setting is crucial for user experience, as it allows the administrator to provide a clean error response instead of letting the connection hang or time out during a total service outage.

Answer

It sets the timeout for health monitor probes.

Answer

It determines the number of concurrent connections allowed.

Answer

It enables compression for the virtual server.

Question 8

A client is experiencing intermittent connection resets when accessing an application via an LTM Virtual Server. The administrator notices that 'OneConnect' is enabled on the virtual server. What is the most likely cause for these resets?

Accepted Answer

The server-side application does not properly handle persistent connections.. OneConnect enables connection pooling, which allows the BIG-IP to keep server-side connections open for reuse. However, if the server-side application or web server doesn't support persistent HTTP connections or lacks proper keep-alive handling, it may prematurely close the connection. This mismatch results in the BIG-IP attempting to use a stale connection, leading to resets when the server rejects the subsequent HTTP requests.

Answer

The client browser is incompatible with HTTP/2.

Answer

The Virtual Server's timeout value is too high.

Answer

The load balancing method is set to 'Least Connections'.

Question 9

Which component is responsible for monitoring the availability of pool members in a BIG-IP environment?

Accepted Answer

The Local Traffic Manager (LTM) monitor, which performs periodic status checks.. Health monitors are the entities that periodically verify the status of pool members. By sending specific probes (TCP, HTTP, ICMP, etc.), they determine if a resource is healthy. If a monitor fails, the BIG-IP marks the resource as 'down' and ceases sending traffic to it, ensuring that users are never routed to unresponsive or malfunctioning application nodes.

Answer

The iRule engine, which executes logic to check server response times.

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The Virtual Server 'Status' setting, which acts as a heartbeat monitor.

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The ConfigSync process, which replicates server status across the device group.

Question 10

Which TWO of the following are benefits of using SNAT (Source Network Address Translation) on a BIG-IP LTM?

Accepted Answer

Simplifies return routing for backend servers.. SNAT simplifies return routing by ensuring traffic returns to the BIG-IP rather than the client, and it hides the backend infrastructure from the public internet. By SNATing the traffic to the BIG-IP's self-IP, the backend server sees the request as coming from the BIG-IP. This prevents asymmetric routing issues and enhances security by abstracting the backend server IP addresses from the end-user environment.

Answer

Increases the encryption speed of the SSL handshake.

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Improves the load balancing algorithm's accuracy.

Answer

Enables the use of cookie-based persistence.