F5 301b Exam Dumps, 301b Practice Test Questions

F5 301b Exam Dumps & Practice Test Questions

Question 1:

In a web application setup, some instances are capable of interpreting the X-Forwarded-For HTTP header, while others assume that the source IP in the request header represents the client’s true address. These instances are organized into two pools: pool_a for those that decode the X-Forwarded-For header and pool_b for those that rely on the source IP in the header.

How should the application determine which pool to forward the request to, based on the presence of the X-Forwarded-For HTTP header?

A. when HTTP_DATA { if {[HTTP::header exists X-Forwarded-For]}{ pool pool_a } else { pool pool_b } }
B. when HTTP_RESPONSE { if {[HTTP::header exists X-Forwarded-For]}{ pool pool_a } else { pool pool_b } }
C. when HTTP_REQUEST { if {[HTTP::header exists X-Forwarded-For]}{ pool pool_a } else { pool pool_b } }
D. when HTTP_OPEN { if {[HTTP::header exists X-Forwarded-For]}{ pool pool_a } else { pool pool_b } }

Answer: C

Explanation:

In this scenario, the application needs to decide which pool to forward the request to based on the presence of the X-Forwarded-For HTTP header. The presence of this header indicates that the client’s true IP address is included in the request by a proxy or load balancer, and it must be checked before deciding which pool to route the request to.

Let’s review the different options:

A. when HTTP_DATA { if {[HTTP::header exists X-Forwarded-For]}{ pool pool_a } else { pool pool_b } }:
This is incorrect because the HTTP_DATA event is not typically used for handling routing decisions or checking headers in most application-level processing within load balancers or proxies. This event generally occurs after the response data is handled, making it unsuitable for deciding which pool to route a request to.
B. when HTTP_RESPONSE { if {[HTTP::header exists X-Forwarded-For]}{ pool pool_a } else { pool pool_b } }:
This is incorrect because the HTTP_RESPONSE event is triggered when the response is generated, not the request. We want to check the X-Forwarded-For header before sending the response, i.e., during the request processing phase, not during the response phase.
C. when HTTP_REQUEST { if {[HTTP::header exists X-Forwarded-For]}{ pool pool_a } else { pool pool_b } }:
This is correct. The HTTP_REQUEST event is triggered when an HTTP request is received. This is the appropriate time to inspect the headers, such as X-Forwarded-For, and determine which pool the request should be forwarded to. If the header exists, it means the request came through a proxy or load balancer that modified the client’s IP, so the system will route the request to pool_a. If the header does not exist, the system assumes that the source IP in the request is the client’s true address and forwards the request to pool_b.
D. when HTTP_OPEN { if {[HTTP::header exists X-Forwarded-For]}{ pool pool_a } else { pool pool_b } }:
This is incorrect because the HTTP_OPEN event is not typically used for making routing decisions. It is more often associated with establishing connections or preparing for further communication, not for processing the HTTP headers and determining the appropriate pool.

In summary, C is the correct answer because the HTTP_REQUEST event is the appropriate moment to inspect the headers (such as X-Forwarded-For) and make a decision about how to route the request.

Question 2:

In a network security context, an iRule is required to block any incoming connections originating from the 10.0.0.0/8 IP range, which is typically used for internal network addresses. Which of the following iRules will correctly reject connections from this IP range?

A. when CLIENT_ACCEPTED { set remote_ip [IP::addr [IP::remote_addr] mask 8] switch $remote_ip { "10.0.0.0" { reject } "11.0.0.0" { pool pool_http1} default { pool http_pool } } }
B. when CLIENT_ACCEPTED { set remote_ip [IP::addr [IP::local_addr] mask 8] switch $remote_ip { "10.0.0.0" { reject } "11.0.0.0" { pool pool_http1} default { pool http_pool } } }
C. when CLIENT_ACCEPTED { set remote_ip [IP::addr [IP::client_addr] mask 255.0.0.0] switch $remote_ip { "10.0.0.0" { reject } "11.0.0.0" { pool pool_http1} default { pool http_pool } } }
D. when CLIENT_ACCEPTED { set remote_ip [IP::addr [IP::local_addr] mask 255.0.0.0] switch $remote_ip { "10.0.0.0" { reject } "11.0.0.0" { pool pool_http1} default { pool http_pool } } }

Answer: C

Explanation:

The goal of this iRule is to block incoming connections from the 10.0.0.0/8 IP range, which includes any IP address in the range from 10.0.0.0 to 10.255.255.255. The iRule needs to check the incoming request's source IP address and reject it if it falls within this range. Let’s break down each option to determine the correct one.

Analysis of the iRules:

A. when CLIENT_ACCEPTED { set remote_ip [IP::addr [IP::remote_addr] mask 8] switch $remote_ip { "10.0.0.0" { reject } "11.0.0.0" { pool pool_http1} default { pool http_pool } } }:
This iRule is incorrect because it uses [IP::remote_addr] to get the source IP. This is a common mistake, as [IP::remote_addr] refers to the address of the machine receiving the request, which is typically the local server address, not the client’s IP address. For blocking client IP addresses, [IP::client_addr] should be used instead.
B. when CLIENT_ACCEPTED { set remote_ip [IP::addr [IP::local_addr] mask 8] switch $remote_ip { "10.0.0.0" { reject } "11.0.0.0" { pool pool_http1} default { pool http_pool } } }:
This iRule is also incorrect because [IP::local_addr] refers to the IP address of the local device (usually the address of the server receiving the request), not the client’s IP address. Again, for blocking client IPs, [IP::client_addr] should be used.
C. when CLIENT_ACCEPTED { set remote_ip [IP::addr [IP::client_addr] mask 255.0.0.0] switch $remote_ip { "10.0.0.0" { reject } "11.0.0.0" { pool pool_http1} default { pool http_pool } } }:
This is correct because it uses [IP::client_addr] to fetch the client’s IP address, and the mask 255.0.0.0 (equivalent to /8 in CIDR notation) correctly matches the 10.0.0.0/8 network range. The switch statement then checks if the IP address matches 10.0.0.0, and if so, the connection is rejected.
D. when CLIENT_ACCEPTED { set remote_ip [IP::addr [IP::local_addr] mask 255.0.0.0] switch $remote_ip { "10.0.0.0" { reject } "11.0.0.0" { pool pool_http1} default { pool http_pool } } }:
This iRule is incorrect because it uses [IP::local_addr], which is the IP address of the local server, rather than the client’s IP address. Therefore, the mask operation would be incorrect for checking the source IP of the incoming request.

The correct iRule is C because it properly checks the client's IP address ([IP::client_addr]) and applies the /8 mask to filter out the 10.0.0.0/8 IP range, rejecting any connection from this internal network range.

Question 3:

In a Local Traffic Manager (LTM) configuration for a trading application, the virtual server is located on VLAN vlan-301 and is accessible via IP address 10.0.0.1:80. The backend trading servers are within the 192.168.0.0/25 subnet. The LTM administrator needs to capture packets for external analysis, including the full payload, to help diagnose an issue.

What is the correct command to execute in order to capture and save the traffic to a file for analysis?

A. tcpdump -vvv -w /var/tmp/trace.cap 'net 192.168.0.0/25'
B. tcpdump -vvv -s 0 -w /var/tmp/trace.cap 'net 192.168.0.0/25'
C. tcpdump -vvv -nni vlan-301 -w /var/tmp/trace.cap 'net 192.168.0.0/25'
D. tcpdump -vvv -s 0 -nni vlan-301 -w /var/tmp/trace.cap 'net 192.168.0.0/25'

Answer: D

Explanation:

The task here is to capture packets for external analysis, including the full payload, on the traffic passing through the LTM, specifically from the backend trading servers in the 192.168.0.0/25 subnet. For this purpose, the capture should be performed with the correct interface, correct filters, and settings to ensure that the full packet payload (not truncated) is captured.

Here’s an analysis of each option:

A. tcpdump -vvv -w /var/tmp/trace.cap 'net 192.168.0.0/25'

Explanation: This command initiates the packet capture with the verbosity level (-vvv) and writes the capture to /var/tmp/trace.cap. The filter 'net 192.168.0.0/25' ensures that only traffic from the 192.168.0.0/25 subnet is captured.
Why it’s incorrect: While this command captures traffic from the correct subnet, it doesn’t specify the interface (-i option) to capture from. Without specifying the network interface, it defaults to capturing from all interfaces, which might not be the intended interface (i.e., vlan-301 in this case). Additionally, the -s 0 option is missing, which ensures that the full packet (including the full payload) is captured.

B. tcpdump -vvv -s 0 -w /var/tmp/trace.cap 'net 192.168.0.0/25'

Explanation: This command also initiates packet capture with verbosity and saves it to /var/tmp/trace.cap. It includes the option -s 0, which ensures that the full packet (including the entire payload) is captured. However, it lacks the specification of the interface to capture from, so the default interface is used, which might not be vlan-301.
Why it’s incorrect: While this command captures the full packet and filters traffic from the subnet correctly, it still does not specify the correct interface (vlan-301), which is necessary for targeting traffic on the specific VLAN.

C. tcpdump -vvv -nni vlan-301 -w /var/tmp/trace.cap 'net 192.168.0.0/25'

Explanation: This command captures traffic on interface vlan-301 with verbosity (-vvv), and applies a network filter for the 192.168.0.0/25 subnet. The -n flag disables name resolution for IP addresses, which speeds up the capture and avoids unnecessary DNS lookups.
Why it’s incorrect: Although it correctly specifies the vlan-301 interface, it lacks the -s 0 option. By default, tcpdump captures only the first 68 bytes of each packet, which might truncate the packet payload. To capture the entire packet, you need the -s 0 option to ensure that the full payload is captured.

D. tcpdump -vvv -s 0 -nni vlan-301 -w /var/tmp/trace.cap 'net 192.168.0.0/25'

Explanation: This is the correct command because it:

Captures traffic on the correct interface, vlan-301, which is where the virtual server resides.
Uses the -s 0 option to ensure that the full packet is captured, including the complete payload.
Applies the correct filter ('net 192.168.0.0/25') to capture traffic only from the backend trading servers’ subnet.
The -vvv option ensures verbose output for better diagnostics, and the -n flag speeds up the capture by disabling name resolution.

The correct option is D because it ensures that the capture is performed on the correct interface (vlan-301), captures the full packet with -s 0, and filters traffic from the required subnet (192.168.0.0/25). This combination meets the requirements for capturing the necessary traffic for external analysis.

Question 4:

A Local Traffic Manager (LTM) specialist has captured a packet trace file named trace.cap from traffic monitoring on the website www.example.com. The virtual server handling this website’s traffic is configured at IP 10.0.0.1:443 within the ApplicationA partition. The captured data is SSL encrypted, and the specialist needs to decrypt the SSL traffic for further analysis.

Which command should the LTM specialist use to decrypt the SSL payload in the captured traffic?

A. ssldump -Aed -nr /var/tmp/trace.cap -k /config/filestore/files_d/Common_d/certificate_d/:Common:www.example.com.crt_1
B. ssldump -Aed -nr /var/tmp/trace.cap -k /config/filestore/files_d/Common_d/certificate_key_d/:Common:www.example.com.key_1
C. ssldump -Aed -nr /var/tmp/trace.cap -k /config/filestore/files_d/ApplicationA_d/certificate_d/:ApplicationA:www.example.com.crt_1
D. ssldump -Aed -nr /var/tmp/trace.cap -k /config/filestore/files_d/ApplicationA_d/certificate_key_d/:ApplicationA:www.example.com.key_1

Answer: D

Explanation:

To decrypt SSL traffic in a Local Traffic Manager (LTM) configuration, it’s necessary to provide the correct private key used to establish the SSL session. The correct private key file is usually located in the same partition where the virtual server is configured. Let’s break down each option:

Key Considerations:

SSL Decryption: To decrypt SSL traffic, the LTM specialist needs access to the private key used by the virtual server to encrypt the traffic.
Partition Context: The virtual server is configured within the ApplicationA partition. Therefore, the correct private key for decryption would be within that same partition.
Certificate and Key Files: The key to decrypt SSL traffic is the private key associated with the SSL certificate. It’s typically stored as a .key file, while the certificate is stored as a .crt file.

Option Breakdown:

A. ssldump -Aed -nr /var/tmp/trace.cap -k /config/filestore/files_d/Common_d/certificate_d/:Common:www.example.com.crt_1:
This command is incorrect because it references a certificate file (.crt), not the private key. While the certificate is used to verify the identity of the server, it cannot be used to decrypt SSL traffic; the private key is required for decryption.
B. ssldump -Aed -nr /var/tmp/trace.cap -k /config/filestore/files_d/Common_d/certificate_key_d/:Common:www.example.com.key_1:
This command references the Common partition and the private key file (.key_1). However, the virtual server is located in the ApplicationA partition, not Common. The private key in the Common partition would not be used for decryption in this case.
C. ssldump -Aed -nr /var/tmp/trace.cap -k /config/filestore/files_d/ApplicationA_d/certificate_d/:ApplicationA:www.example.com.crt_1:
This command references the certificate file (.crt), which, as mentioned earlier, cannot be used to decrypt SSL traffic. The certificate_d directory is incorrect because the .crt file alone is not enough to decrypt the SSL traffic.
D. ssldump -Aed -nr /var/tmp/trace.cap -k /config/filestore/files_d/ApplicationA_d/certificate_key_d/:ApplicationA:www.example.com.key_1:
This command is correct because:

It correctly refers to the ApplicationA partition where the virtual server is located.
It specifies the private key file (.key_1), which is necessary to decrypt SSL traffic.
The path and partition context are appropriate for the virtual server handling traffic for www.example.com in the ApplicationA partition.

The correct command to decrypt the SSL traffic is D because it references the correct partition (ApplicationA), and more importantly, it points to the private key file, which is required for SSL decryption. The other options either reference incorrect partitions or use the certificate file instead of the private key, making them unsuitable for SSL decryption.

Question 5:

An LTM (Local Traffic Manager) Specialist needs to capture a packet trace for a virtual server configured with a standard FastL4 profile. The virtual server’s IP is 10.0.0.1:443 and is located on VLAN vlan301. The specialist aims to capture the data payload of this server without affecting the operation of any other virtual servers on the system.

What is the correct approach for the LTM Specialist to follow?

A. The standard FastL4 profile should have PVA (Packet Velocity Acceleration) disabled. After that, the packet capture can be initiated using the command tcpdump -ni vlan301.
B. Execute the packet capture command tcpdump -ni vlan301 without modifying the FastL4 profile or PVA acceleration settings.
C. Create a new FastL4 profile with PVA acceleration disabled, then capture packets using tcpdump -ni vlan301.
D. Since the LTM device is under light load, the traffic should be mirrored to a dedicated sniffing device, where the capture will be executed using tcpdump -ni vlan301.

Answer: B

Explanation:

To capture the packet trace on an LTM system, especially for a virtual server configured with a FastL4 profile, several key factors need to be considered to ensure that the capture is performed correctly while not interrupting the operation of other virtual servers.

Key Considerations:

FastL4 Profile: The FastL4 profile on an LTM is used to handle Layer 4 (transport layer) traffic. It optimizes the processing of network traffic by bypassing certain layers of inspection that would typically occur with higher-level profiles such as HTTP, SSL, or TCP. FastL4 essentially forwards traffic in a way that’s faster but with less granularity in terms of traffic inspection.
PVA (Packet Velocity Acceleration): PVA is a hardware acceleration feature used to optimize traffic processing. If PVA is enabled, it can speed up the processing of packets but could potentially interfere with packet captures because of how the traffic is offloaded.
Packet Capture on VLAN: To capture traffic for a specific virtual server, the packet capture must be done on the correct network interface, which in this case is vlan301.

Option Breakdown:

A. The standard FastL4 profile should have PVA (Packet Velocity Acceleration) disabled. After that, the packet capture can be initiated using the command tcpdump -ni vlan301.

Why it’s incorrect: Although disabling PVA could ensure that packets are processed by the LTM instead of being offloaded to hardware, there is no indication that PVA should specifically be disabled for the packet capture. Disabling PVA would be an unnecessary step if the goal is simply to capture traffic. Additionally, disabling PVA could have a negative impact on performance if it’s an environment that relies on hardware acceleration for handling high traffic volumes.

B. Execute the packet capture command tcpdump -ni vlan301 without modifying the FastL4 profile or PVA acceleration settings.

Why it’s correct: This is the simplest and most direct approach. The LTM system is capable of capturing packets directly from the interface vlan301, and no changes to the FastL4 profile or PVA settings are required for basic packet capture. Capturing packets using the tcpdump -ni vlan301 command will allow the specialist to gather the data traffic without interfering with the system’s configuration or performance. This approach is effective for gathering the necessary traffic for analysis.

C. Create a new FastL4 profile with PVA acceleration disabled, then capture packets using tcpdump -ni vlan301.

Why it’s incorrect: Creating a new FastL4 profile and disabling PVA is an unnecessary step. The specialist doesn’t need to modify the profile or disable PVA just to capture traffic. In fact, creating a new profile could cause unnecessary complexity and may not improve the capture process. The current profile configuration is sufficient for capturing traffic on vlan301.

D. Since the LTM device is under light load, the traffic should be mirrored to a dedicated sniffing device, where the capture will be executed using tcpdump -ni vlan301.

Why it’s incorrect: While traffic mirroring is useful in some cases for network analysis, it adds an additional layer of complexity. Mirroring the traffic to a dedicated sniffing device is not required in this case since the LTM itself can perform packet capture directly on the interface. This approach could be useful for more complex scenarios but is not needed in this case where tcpdump can directly capture the traffic from the correct VLAN interface.

The correct approach is B, as it simplifies the task and avoids unnecessary changes to the FastL4 profile or the PVA settings. The tcpdump -ni vlan301 command will directly capture the traffic on the required interface without affecting the operation of other virtual servers, which is exactly what the LTM specialist needs to do for this scenario.

Question 6:

An administrator is configuring a Local Traffic Manager (LTM) for a web application that needs to route traffic based on the presence of a specific HTTP header.

Which iRule would you use to forward requests to different pools based on the existence of a custom header, X-Client-ID?

A. when HTTP_REQUEST { if {[HTTP::header exists X-Client-ID]} { pool client_pool } else { pool default_pool } }
B. when HTTP_RESPONSE { if {[HTTP::header exists X-Client-ID]} { pool client_pool } else { pool default_pool } }
C. when HTTP_REQUEST { if {[HTTP::header exists X-Client-ID]} { pool default_pool } else { pool client_pool } }
D. when HTTP_DATA { if {[HTTP::header exists X-Client-ID]} { pool client_pool } else { pool default_pool } }

Answer: A

Explanation:

In this scenario, the administrator needs to route traffic based on the presence of a custom HTTP header, X-Client-ID. iRules in F5 Local Traffic Manager (LTM) are used to inspect, modify, or route traffic based on specific conditions. The key here is to inspect the request for the existence of a custom header (X-Client-ID) and then forward the request to the appropriate pool.

Breakdown of the Options:

A. when HTTP_REQUEST { if {[HTTP::header exists X-Client-ID]} { pool client_pool } else { pool default_pool } }

Correct answer. This iRule triggers when an HTTP request is received, which is appropriate because the goal is to inspect the HTTP header and route the request based on the existence of the X-Client-ID header. If the header exists, the request is forwarded to the client_pool; otherwise, it is forwarded to the default_pool.
Why it’s correct: The iRule properly checks for the header during the HTTP request phase, which is when headers are available to inspect, and it ensures traffic is routed to the correct pool based on that check.

B. when HTTP_RESPONSE { if {[HTTP::header exists X-Client-ID]} { pool client_pool } else { pool default_pool } }

Incorrect. This iRule is triggered during the HTTP response phase, which occurs after the server has processed the request. At this stage, the request has already been routed to a pool, and the response is being generated. HTTP headers cannot influence the routing decisions made at this point, as routing should occur based on the request, not the response.
Why it’s incorrect: The condition should be checked during the request phase (HTTP_REQUEST) rather than the response phase (HTTP_RESPONSE).

C. when HTTP_REQUEST { if {[HTTP::header exists X-Client-ID]} { pool default_pool } else { pool client_pool } }

Incorrect. This iRule is very similar to option A, but it routes traffic to the default_pool when the X-Client-ID header exists, and to the client_pool when the header does not exist. This is the opposite of what is desired in the scenario. The goal is to forward requests to the client_pool when the X-Client-ID header exists, not when it is absent.
Why it’s incorrect: The pools are reversed compared to what is needed for this scenario.

D. when HTTP_DATA { if {[HTTP::header exists X-Client-ID]} { pool client_pool } else { pool default_pool } }

Incorrect. The HTTP_DATA event occurs when the body of the HTTP request is available for inspection, typically after headers have been processed. Since the goal is to route traffic based on the header, the inspection should occur earlier, during the HTTP_REQUEST phase, when the header is still part of the request and not after data has been processed.
Why it’s incorrect: The header should be inspected during the request phase, not during the data phase.

The correct iRule for this scenario is A, as it checks the presence of the X-Client-ID header during the HTTP_REQUEST phase and routes the traffic to the appropriate pool based on whether the header exists or not. The other options either check the wrong phase of the HTTP transaction or reverse the pool assignment.

Question 7:

In an LTM setup, there is a need to block traffic from a specific geographic region using an iRule. What would be the correct approach to deny all traffic from the country "Germany"?

A. when CLIENT_ACCEPTED { if {[IP::geoip country] eq "DE"} { reject } }
B. when CLIENT_ACCEPTED { if {[IP::geoip country] eq "DE"} { pool block_pool } else { pool default_pool } }
C. when CLIENT_ACCEPTED { if {[IP::geoip country] eq "DE"} { reject } default { pool default_pool } }
D. when CLIENT_ACCEPTED { set geo_country [IP::geoip country]; if { $geo_country eq "DE" } { reject } else { pool default_pool } }

Answer: A

Explanation:

In this scenario, the goal is to block traffic from the country "Germany" using geographic IP lookup functionality available in F5 Local Traffic Manager (LTM). The appropriate solution should inspect the geographic location of the incoming IP address and reject the traffic if it originates from Germany.

Breakdown of the Options:

A. when CLIENT_ACCEPTED { if {[IP::geoip country] eq "DE"} { reject } }

Correct answer. This iRule checks the country of origin for the incoming traffic by using the IP::geoip country function. If the country is Germany (denoted by "DE"), it immediately rejects the connection. This solution directly addresses the requirement to block traffic from Germany.
Why it’s correct: The iRule directly rejects traffic from Germany during the CLIENT_ACCEPTED phase, which is when the IP address is available to inspect.

B. when CLIENT_ACCEPTED { if {[IP::geoip country] eq "DE"} { pool block_pool } else { pool default_pool } }

Incorrect. This iRule would direct traffic from Germany to a pool named block_pool, but this does not reject the traffic, and it still processes the request, which is not the intended solution. The task is to block the traffic, not reroute it.
Why it’s incorrect: The goal is to reject the traffic, not route it to a separate pool.

C. when CLIENT_ACCEPTED { if {[IP::geoip country] eq "DE"} { reject } default { pool default_pool } }

Incorrect. While this iRule does reject traffic from Germany, the default { pool default_pool } part is unnecessary and redundant. This would result in forwarding traffic that is not from Germany to the default_pool, which doesn't align with the specific requirement of simply blocking traffic from Germany without additional routing logic.
Why it’s incorrect: The extra pool forwarding logic is unnecessary. Blocking Germany traffic should be straightforward without default pool redirection.

D. when CLIENT_ACCEPTED { set geo_country [IP::geoip country]; if { $geo_country eq "DE" } { reject } else { pool default_pool } }

Incorrect. This iRule uses an intermediate variable (geo_country), but it ultimately does the same thing as option A, which is to reject traffic from Germany. However, the additional else { pool default_pool } part is redundant. If the goal is to block Germany traffic, the else portion that forwards traffic to default_pool is unnecessary.
Why it’s incorrect: The else portion that routes traffic to default_pool is not needed when the goal is to reject traffic from Germany. The simplest approach is to directly reject traffic from Germany without adding extra routing logic.

The most straightforward and efficient approach is A, where the iRule directly rejects any traffic from Germany based on the country code "DE". The other options introduce unnecessary complexity or redirect traffic when it should be blocked entirely.

Question 8:

How can an LTM administrator configure a virtual server to reject all connections from clients whose IP addresses are within the 192.168.0.0/16 subnet?

A. when CLIENT_ACCEPTED { if {[IP::addr [IP::remote_addr] equals 192.168.0.0/16]} { reject } }
B. when CLIENT_ACCEPTED { set ip [IP::addr [IP::remote_addr]]; if { [IP::match $ip 192.168.0.0/16] } { reject } }
C. when CLIENT_ACCEPTED { if {[IP::addr [IP::remote_addr] equals 192.168.0.0/16]} { reject } default { pool default_pool } }
D. when CLIENT_ACCEPTED { if {[IP::addr [IP::remote_addr] mask 255.255.0.0] equals 192.168.0.0} { reject } }

Answer: B

Explanation:

In this scenario, the goal is to reject all connections from clients within the 192.168.0.0/16 subnet. The iRule should inspect the incoming request's IP address and check if it falls within this specific subnet.

Breakdown of the Options:

A. when CLIENT_ACCEPTED { if {[IP::addr [IP::remote_addr] equals 192.168.0.0/16]} { reject } }

Incorrect. The equals operator is not the right choice for checking if an IP address falls within a subnet. The proper approach is to use the match operator or similar methods to evaluate whether the IP address is within a specific range, not equals. This would not work as expected for a subnet check.
Why it’s incorrect: The equals operator doesn't support subnet matching and will not correctly reject the IP addresses within the range.

B. when CLIENT_ACCEPTED { set ip [IP::addr [IP::remote_addr]]; if { [IP::match $ip 192.168.0.0/16] } { reject } }

Correct answer. This iRule sets a variable ip to the client's IP address and then checks if it matches the 192.168.0.0/16 subnet using the IP::match function. The IP::match function is designed to check if the IP address falls within a specified range or subnet. If the condition is met, the connection is rejected.
Why it’s correct: This solution correctly checks if the incoming IP address belongs to the 192.168.0.0/16 subnet and rejects the connection accordingly.

C. when CLIENT_ACCEPTED { if {[IP::addr [IP::remote_addr] equals 192.168.0.0/16]} { reject } default { pool default_pool } }

Incorrect. Similar to option A, this uses the equals operator for subnet matching, which is incorrect. Additionally, the default { pool default_pool } part is unnecessary if the goal is to simply reject connections from this subnet.
Why it’s incorrect: The equals operator does not work for subnet comparisons, and the default { pool default_pool } part adds unnecessary complexity to the iRule.

D. when CLIENT_ACCEPTED { if {[IP::addr [IP::remote_addr] mask 255.255.0.0] equals 192.168.0.0} { reject } }

Incorrect. This approach uses the mask function to apply a subnet mask, which modifies the original IP address. However, the method doesn't correctly evaluate whether the IP address belongs to the subnet 192.168.0.0/16. The comparison with equals 192.168.0.0 would not correctly match all addresses in the 192.168.0.0/16 range.
Why it’s incorrect: The comparison with equals after applying the subnet mask isn't effective for checking whether an IP address belongs to a specific subnet.

The correct approach is B, where the iRule uses the IP::match function to check if the client’s IP address is within the 192.168.0.0/16 subnet and reject it accordingly. The other options either use incorrect comparison methods or add unnecessary logic that complicates the iRule without addressing the primary goal of rejecting the traffic from the specified subnet.

Question 9:

Which command should be used to verify the current active traffic profiles applied to a virtual server within a Local Traffic Manager (LTM)?

A. show ltm virtual-server <virtual_server_name> profile
B. show running-config virtual-server <virtual_server_name>
C. show virtual-server <virtual_server_name> profile
D. show ltm virtual <virtual_server_name> profiles

Answer: D

Explanation:

To verify the current active traffic profiles applied to a virtual server in a Local Traffic Manager (LTM), the correct command to use is "show ltm virtual <virtual_server_name> profiles".

Breakdown of the Options:

A. show ltm virtual-server <virtual_server_name> profile

Incorrect. This command structure is slightly off. The correct command structure uses "show ltm virtual", not "show ltm virtual-server". While the idea of verifying profiles is correct, this command would not work due to the incorrect syntax.
Why it's incorrect: The virtual-server keyword isn't used in this context.

B. show running-config virtual-server <virtual_server_name>

Incorrect. This command shows the running configuration of a specific virtual server, but it does not focus on the traffic profiles. The output from this command may include many other configuration details of the virtual server, not just the profiles.
Why it's incorrect: While it provides a broader view of the server configuration, it does not specifically focus on the traffic profiles applied.

C. show virtual-server <virtual_server_name> profile

Incorrect. This command is not valid in LTM's command syntax. The correct command structure would involve "show ltm virtual" rather than just "show virtual-server."
Why it's incorrect: The command structure is not valid in LTM and will likely result in an error.

D. show ltm virtual <virtual_server_name> profiles

Correct answer. This is the correct command to use in LTM to display the traffic profiles that are currently applied to a specified virtual server. The "show ltm virtual" command syntax is correct, and using profiles will filter and display the active traffic profiles.
Why it's correct: This command properly targets the virtual server's active traffic profiles, making it the most direct and effective command for the task.

To verify the active traffic profiles applied to a virtual server in LTM, the correct command is D, "show ltm virtual <virtual_server_name> profiles". This command is specific and provides the necessary details about the traffic profiles.

Question 10:

If a Local Traffic Manager (LTM) specialist needs to trace SSL connections for a virtual server but only wants to capture the handshake and not the full data payload, which of the following tcpdump commands should be used?

A. tcpdump -vvv -s 128 -w /var/tmp/trace.cap 'port 443'
B. tcpdump -vvv -s 0 -w /var/tmp/trace.cap 'port 443 and not tcp port 80'
C. tcpdump -vvv -s 128 -w /var/tmp/trace.cap 'tcp port 443'
D. tcpdump -vvv -s 0 -w /var/tmp/trace.cap 'port 443'

Answer: A

Explanation:

To capture only the SSL handshake and exclude the full data payload, you would want to capture the initial connection setup and the associated handshake messages but not the encrypted application data that follows.

Breakdown of the Options:

A. tcpdump -vvv -s 128 -w /var/tmp/trace.cap 'port 443'

Correct answer. This command captures packets on port 443 (typically used for SSL/TLS connections) and limits the capture size to 128 bytes, which is enough to capture the SSL handshake but not the entire payload.
Why it's correct: The -s 128 option ensures that only the initial handshake is captured (since the handshake typically occurs within the first 128 bytes of the connection), while ignoring the rest of the data after the handshake. It captures the packets on port 443, which is the port used for SSL traffic, without unnecessarily capturing the full data payload.

B. tcpdump -vvv -s 0 -w /var/tmp/trace.cap 'port 443 and not tcp port 80'

Incorrect. This command is attempting to capture SSL traffic on port 443 and exclude HTTP traffic on port 80. However, the -s 0 option is asking for the full packet size, which means it will capture both the handshake and the data payload, which is not required in this case. Also, the exclusion of port 80 is unnecessary since port 80 is not relevant to the SSL traffic on port 443.
Why it's incorrect: The exclusion of port 80 is irrelevant, and capturing full packets (with -s 0) would include unnecessary data payload.

C. tcpdump -vvv -s 128 -w /var/tmp/trace.cap 'tcp port 443'

Incorrect. While this command captures traffic on TCP port 443 and limits the capture size to 128 bytes (which is appropriate for capturing the handshake), the -s 128 option might still capture more than needed. It’s also less precise than the option used in A.
Why it's incorrect: This command is technically correct in terms of limiting the capture size, but option A is more explicit in capturing only the handshake on port 443.

D. tcpdump -vvv -s 0 -w /var/tmp/trace.cap 'port 443'

Incorrect. This command captures all packets on port 443 without limiting the packet size. The -s 0 option means it will capture the full packets, including the encrypted application data after the handshake, which is not required.
Why it's incorrect: Capturing full packets (with -s 0) will include both the handshake and the subsequent encrypted data, making it less efficient for the task of tracing only the SSL handshake.

To capture only the SSL handshake and not the full data payload, the best option is A, using the -s 128 option to limit the capture size and ensuring that only the handshake information is captured.