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Question 1 of 30
1. Question
In a corporate environment, a network administrator is tasked with implementing a security policy that governs access control for sensitive data. The policy must ensure that only authorized personnel can access specific resources based on their roles within the organization. The administrator decides to use Role-Based Access Control (RBAC) as the framework for this policy. Which of the following best describes the primary advantage of using RBAC in this scenario?
Correct
For instance, if a user changes roles within the organization, the administrator can simply reassign the user to a different role with the appropriate permissions, rather than having to modify individual access rights. This significantly reduces the administrative overhead and potential for errors that can occur when managing permissions on a per-user basis. Moreover, RBAC enhances security by ensuring that users only have access to the resources necessary for their job functions, thereby adhering to the principle of least privilege. This principle is crucial in minimizing the risk of unauthorized access to sensitive data, as it limits exposure to only those who need it for their roles. In contrast, the other options present misconceptions about RBAC. While individual user attributes can be considered in access control, RBAC fundamentally relies on roles rather than individual characteristics. Dynamic access control based on real-time behavior is more aligned with Attribute-Based Access Control (ABAC), which is a different model altogether. Lastly, while documentation is important in any access control model, RBAC is designed to reduce complexity, not increase it, by centralizing permissions management around roles. Thus, the effective implementation of RBAC can lead to a more secure and manageable access control environment in a corporate setting.
Incorrect
For instance, if a user changes roles within the organization, the administrator can simply reassign the user to a different role with the appropriate permissions, rather than having to modify individual access rights. This significantly reduces the administrative overhead and potential for errors that can occur when managing permissions on a per-user basis. Moreover, RBAC enhances security by ensuring that users only have access to the resources necessary for their job functions, thereby adhering to the principle of least privilege. This principle is crucial in minimizing the risk of unauthorized access to sensitive data, as it limits exposure to only those who need it for their roles. In contrast, the other options present misconceptions about RBAC. While individual user attributes can be considered in access control, RBAC fundamentally relies on roles rather than individual characteristics. Dynamic access control based on real-time behavior is more aligned with Attribute-Based Access Control (ABAC), which is a different model altogether. Lastly, while documentation is important in any access control model, RBAC is designed to reduce complexity, not increase it, by centralizing permissions management around roles. Thus, the effective implementation of RBAC can lead to a more secure and manageable access control environment in a corporate setting.
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Question 2 of 30
2. Question
A company is planning to design a new network infrastructure to support a growing number of remote employees. The network must ensure high availability, scalability, and security while minimizing latency. The design team is considering implementing a hierarchical network model. Which of the following best describes the advantages of using a hierarchical model in this scenario?
Correct
Firstly, the hierarchical model enhances traffic management and segmentation. By separating the network into layers, each layer can be optimized for specific functions. For instance, the core layer is designed for high-speed data transfer, while the distribution layer can implement policies for routing and access control. This segmentation allows for better control over traffic flows, which can significantly improve overall network performance and security. For example, security policies can be enforced at the distribution layer, ensuring that only authorized traffic is allowed to reach sensitive areas of the network. Secondly, the hierarchical model supports scalability. As the company grows and the number of remote employees increases, the network can be expanded more easily by adding additional access layer switches without disrupting the existing infrastructure. This modularity is crucial for accommodating future growth without requiring a complete redesign of the network. Moreover, while the hierarchical model does simplify certain aspects of network design, it does not inherently reduce the number of devices required or eliminate redundancy. In fact, redundancy is a critical component of high availability, and the hierarchical model often incorporates redundant paths and devices to ensure that the network remains operational even in the event of a failure. In summary, the hierarchical network model is advantageous in this scenario because it allows for improved traffic management and segmentation, which enhances both performance and security. It also provides a scalable framework that can adapt to the company’s growth, making it a suitable choice for supporting a growing number of remote employees.
Incorrect
Firstly, the hierarchical model enhances traffic management and segmentation. By separating the network into layers, each layer can be optimized for specific functions. For instance, the core layer is designed for high-speed data transfer, while the distribution layer can implement policies for routing and access control. This segmentation allows for better control over traffic flows, which can significantly improve overall network performance and security. For example, security policies can be enforced at the distribution layer, ensuring that only authorized traffic is allowed to reach sensitive areas of the network. Secondly, the hierarchical model supports scalability. As the company grows and the number of remote employees increases, the network can be expanded more easily by adding additional access layer switches without disrupting the existing infrastructure. This modularity is crucial for accommodating future growth without requiring a complete redesign of the network. Moreover, while the hierarchical model does simplify certain aspects of network design, it does not inherently reduce the number of devices required or eliminate redundancy. In fact, redundancy is a critical component of high availability, and the hierarchical model often incorporates redundant paths and devices to ensure that the network remains operational even in the event of a failure. In summary, the hierarchical network model is advantageous in this scenario because it allows for improved traffic management and segmentation, which enhances both performance and security. It also provides a scalable framework that can adapt to the company’s growth, making it a suitable choice for supporting a growing number of remote employees.
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Question 3 of 30
3. Question
In a corporate network, the IT department is tasked with implementing Quality of Service (QoS) to prioritize voice traffic over regular data traffic. The network consists of multiple VLANs, and the IT team decides to use Differentiated Services Code Point (DSCP) values to classify and mark packets. If voice packets are marked with a DSCP value of 46 (Expedited Forwarding), and data packets are marked with a DSCP value of 0 (Best Effort), what is the expected behavior of the network when it experiences congestion, and how does this marking influence the queuing mechanisms in the routers?
Correct
This prioritization is achieved through various queuing mechanisms, such as Priority Queuing (PQ) or Low Latency Queuing (LLQ), which allow voice packets to be placed in a higher-priority queue. As a result, these packets are forwarded with minimal delay, ensuring that voice calls maintain their quality and clarity. In contrast, data packets, which are marked as Best Effort, may experience increased latency, jitter, or even be dropped altogether if the network is heavily congested. The implications of this marking and prioritization are significant for maintaining the quality of real-time applications. If both voice and data packets were treated equally, as suggested in option b, it would lead to a degradation of voice quality, making conversations difficult to understand. Similarly, if data packets were prioritized over voice packets, as in option c, it would compromise the integrity of voice communications, which rely on timely delivery. Lastly, queuing both types of packets together without prioritization, as in option d, would result in random drops, further exacerbating the issues faced by voice traffic. Thus, the correct understanding of DSCP marking and its impact on QoS mechanisms is essential for network engineers to ensure optimal performance for critical applications, particularly in environments where voice traffic is prevalent.
Incorrect
This prioritization is achieved through various queuing mechanisms, such as Priority Queuing (PQ) or Low Latency Queuing (LLQ), which allow voice packets to be placed in a higher-priority queue. As a result, these packets are forwarded with minimal delay, ensuring that voice calls maintain their quality and clarity. In contrast, data packets, which are marked as Best Effort, may experience increased latency, jitter, or even be dropped altogether if the network is heavily congested. The implications of this marking and prioritization are significant for maintaining the quality of real-time applications. If both voice and data packets were treated equally, as suggested in option b, it would lead to a degradation of voice quality, making conversations difficult to understand. Similarly, if data packets were prioritized over voice packets, as in option c, it would compromise the integrity of voice communications, which rely on timely delivery. Lastly, queuing both types of packets together without prioritization, as in option d, would result in random drops, further exacerbating the issues faced by voice traffic. Thus, the correct understanding of DSCP marking and its impact on QoS mechanisms is essential for network engineers to ensure optimal performance for critical applications, particularly in environments where voice traffic is prevalent.
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Question 4 of 30
4. Question
In a corporate network, a DHCP server is configured to allocate IP addresses from the range 192.168.1.100 to 192.168.1.200. The server is set to lease each IP address for 24 hours. If a client device requests an IP address at 10:00 AM and does not renew the lease, what will happen to the IP address at 10:00 AM the following day, and how does this relate to the DHCP lease process and the concept of address exhaustion?
Correct
If the client does not renew the lease, the DHCP server will release the IP address back into the pool of available addresses at the end of the lease period. This means that at 10:00 AM the following day, the IP address that was initially assigned to the client will be available for reassignment to any other device that requests an IP address. This process is crucial for efficient IP address management, especially in environments where devices frequently connect and disconnect from the network. Address exhaustion can occur if the DHCP server’s pool of available addresses is too small relative to the number of devices on the network. In this scenario, if the DHCP server has a limited range (only 101 addresses from 192.168.1.100 to 192.168.1.200), and many devices are connecting and disconnecting, it is essential to manage leases effectively to avoid running out of available addresses. The ability to reclaim IP addresses after their lease expires is a fundamental aspect of DHCP that helps maintain network efficiency and connectivity.
Incorrect
If the client does not renew the lease, the DHCP server will release the IP address back into the pool of available addresses at the end of the lease period. This means that at 10:00 AM the following day, the IP address that was initially assigned to the client will be available for reassignment to any other device that requests an IP address. This process is crucial for efficient IP address management, especially in environments where devices frequently connect and disconnect from the network. Address exhaustion can occur if the DHCP server’s pool of available addresses is too small relative to the number of devices on the network. In this scenario, if the DHCP server has a limited range (only 101 addresses from 192.168.1.100 to 192.168.1.200), and many devices are connecting and disconnecting, it is essential to manage leases effectively to avoid running out of available addresses. The ability to reclaim IP addresses after their lease expires is a fundamental aspect of DHCP that helps maintain network efficiency and connectivity.
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Question 5 of 30
5. Question
In a large enterprise network, the IT department is tasked with creating a comprehensive network documentation standard to ensure consistency and clarity across all network diagrams and configurations. The documentation must include not only the physical and logical topology but also the protocols in use, IP addressing schemes, and device configurations. Which of the following practices best aligns with established network documentation standards to enhance maintainability and troubleshooting efficiency?
Correct
In contrast, creating individual documentation for each device without a unified structure can lead to significant inconsistencies. This approach may result in critical information being overlooked or misrepresented, making it difficult for network engineers to piece together the overall network picture. Similarly, relying solely on vendor documentation is inadequate, as it often lacks the specific context of how devices are configured within the enterprise environment. Vendor documentation may not reflect custom configurations or the unique topology of the network, which can lead to confusion during troubleshooting. Implementing a version control system is a positive step, but if staff are not trained on the importance of maintaining accurate and up-to-date records, the documentation may quickly become obsolete. This can create a false sense of security, as engineers may assume they are working with the latest information when, in reality, it may not reflect the current state of the network. Thus, the best practice is to utilize a standardized template for all network diagrams, ensuring that they are updated in real-time as changes occur. This approach not only enhances maintainability but also significantly improves troubleshooting efficiency, as all team members can rely on a consistent and comprehensive source of information.
Incorrect
In contrast, creating individual documentation for each device without a unified structure can lead to significant inconsistencies. This approach may result in critical information being overlooked or misrepresented, making it difficult for network engineers to piece together the overall network picture. Similarly, relying solely on vendor documentation is inadequate, as it often lacks the specific context of how devices are configured within the enterprise environment. Vendor documentation may not reflect custom configurations or the unique topology of the network, which can lead to confusion during troubleshooting. Implementing a version control system is a positive step, but if staff are not trained on the importance of maintaining accurate and up-to-date records, the documentation may quickly become obsolete. This can create a false sense of security, as engineers may assume they are working with the latest information when, in reality, it may not reflect the current state of the network. Thus, the best practice is to utilize a standardized template for all network diagrams, ensuring that they are updated in real-time as changes occur. This approach not only enhances maintainability but also significantly improves troubleshooting efficiency, as all team members can rely on a consistent and comprehensive source of information.
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Question 6 of 30
6. Question
In a corporate network, a network engineer is tasked with implementing a secure routing protocol to ensure the confidentiality and integrity of routing updates. The engineer considers using protocols such as OSPFv3 with IPsec, EIGRP with MD5 authentication, and BGP with TCP MD5 signatures. Given the need for both authentication and encryption of routing information, which combination of protocols and features would provide the most robust security for the routing updates in this scenario?
Correct
EIGRP with MD5 authentication provides a level of security by ensuring that only routers with the correct key can participate in the routing process. However, it does not encrypt the routing updates, leaving them vulnerable to eavesdropping. Similarly, BGP with TCP MD5 signatures offers authentication for BGP sessions but lacks encryption, which means that while the integrity of the routing information is protected, the information itself can still be intercepted. On the other hand, OSPFv2 with plain text authentication is the least secure option, as it does not provide any encryption, making it susceptible to both interception and spoofing attacks. Thus, the most secure option is OSPFv3 with IPsec, as it combines both encryption and authentication, ensuring that routing updates are protected from both unauthorized access and eavesdropping. This approach aligns with best practices for securing routing protocols in enterprise environments, where the confidentiality and integrity of routing information are paramount.
Incorrect
EIGRP with MD5 authentication provides a level of security by ensuring that only routers with the correct key can participate in the routing process. However, it does not encrypt the routing updates, leaving them vulnerable to eavesdropping. Similarly, BGP with TCP MD5 signatures offers authentication for BGP sessions but lacks encryption, which means that while the integrity of the routing information is protected, the information itself can still be intercepted. On the other hand, OSPFv2 with plain text authentication is the least secure option, as it does not provide any encryption, making it susceptible to both interception and spoofing attacks. Thus, the most secure option is OSPFv3 with IPsec, as it combines both encryption and authentication, ensuring that routing updates are protected from both unauthorized access and eavesdropping. This approach aligns with best practices for securing routing protocols in enterprise environments, where the confidentiality and integrity of routing information are paramount.
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Question 7 of 30
7. Question
In a network utilizing IPv6, a company has implemented OSPFv3 as its routing protocol. The network consists of multiple routers, and the company is experiencing issues with route convergence times. The network administrator wants to optimize the OSPFv3 configuration to improve convergence. Which of the following configurations would most effectively enhance the OSPFv3 convergence time in this scenario?
Correct
While increasing the OSPFv3 cost metric can influence route selection, it does not directly affect convergence times. Similarly, route summarization can help reduce the size of the routing table and improve efficiency, but it does not inherently speed up the convergence process. Enabling OSPFv3 authentication is essential for securing routing updates, but it does not contribute to faster convergence. In summary, the most effective way to improve OSPFv3 convergence in this scenario is to adjust the hello and dead intervals, allowing for quicker detection of neighbor states and faster recalculation of routes. This approach directly addresses the convergence issue by ensuring that routers can respond promptly to changes in the network topology.
Incorrect
While increasing the OSPFv3 cost metric can influence route selection, it does not directly affect convergence times. Similarly, route summarization can help reduce the size of the routing table and improve efficiency, but it does not inherently speed up the convergence process. Enabling OSPFv3 authentication is essential for securing routing updates, but it does not contribute to faster convergence. In summary, the most effective way to improve OSPFv3 convergence in this scenario is to adjust the hello and dead intervals, allowing for quicker detection of neighbor states and faster recalculation of routes. This approach directly addresses the convergence issue by ensuring that routers can respond promptly to changes in the network topology.
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Question 8 of 30
8. Question
In a large enterprise network, a network engineer is tasked with implementing policy-based automation to manage the routing protocols dynamically based on network performance metrics. The engineer decides to use a combination of Cisco DNA Center and Cisco IOS XE to achieve this. Given a scenario where the network experiences a sudden increase in traffic, which of the following actions should the engineer prioritize to ensure optimal routing performance while adhering to policy-based automation principles?
Correct
For instance, if the network is using OSPF, the engineer can modify the cost of links based on their utilization, ensuring that traffic is rerouted through less congested paths. This dynamic adjustment is a core principle of policy-based automation, which emphasizes responsiveness and adaptability. On the other hand, manually configuring static routes (option b) is not ideal in a dynamic environment, as it requires constant updates and does not respond to real-time changes. Disabling all routing protocols (option c) would lead to a complete loss of routing capabilities, resulting in network downtime and instability. Increasing bandwidth indiscriminately (option d) may not be a cost-effective solution and could lead to underutilization of resources if not aligned with actual traffic patterns. Thus, the most effective strategy in this scenario is to utilize policy-based automation to dynamically adjust routing metrics, ensuring that the network remains efficient and responsive to traffic demands. This approach not only optimizes performance but also aligns with best practices in modern network management, where automation and real-time analytics play a pivotal role in operational efficiency.
Incorrect
For instance, if the network is using OSPF, the engineer can modify the cost of links based on their utilization, ensuring that traffic is rerouted through less congested paths. This dynamic adjustment is a core principle of policy-based automation, which emphasizes responsiveness and adaptability. On the other hand, manually configuring static routes (option b) is not ideal in a dynamic environment, as it requires constant updates and does not respond to real-time changes. Disabling all routing protocols (option c) would lead to a complete loss of routing capabilities, resulting in network downtime and instability. Increasing bandwidth indiscriminately (option d) may not be a cost-effective solution and could lead to underutilization of resources if not aligned with actual traffic patterns. Thus, the most effective strategy in this scenario is to utilize policy-based automation to dynamically adjust routing metrics, ensuring that the network remains efficient and responsive to traffic demands. This approach not only optimizes performance but also aligns with best practices in modern network management, where automation and real-time analytics play a pivotal role in operational efficiency.
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Question 9 of 30
9. Question
In a corporate environment, a network engineer is tasked with designing a wireless network that supports Voice over IP (VoIP) applications. The engineer must choose a wireless routing protocol that optimally manages bandwidth and minimizes latency for real-time applications. Considering the requirements for Quality of Service (QoS) and the need for efficient handling of multiple access points, which wireless routing protocol would be the most suitable for this scenario?
Correct
On the other hand, Point Coordination Function (PCF) and Distributed Coordination Function (DCF) do not provide the same level of QoS management as EDCA. PCF is a polling-based protocol that can introduce delays, making it less suitable for real-time applications like VoIP. DCF, while it is the fundamental access method for wireless LANs, operates on a contention basis and does not prioritize traffic, which can lead to increased latency for time-sensitive applications. Hybrid Coordination Function (HCF) combines elements of both EDCA and PCF but is primarily focused on providing a balance between contention-based and contention-free access. However, it does not specifically enhance QoS for VoIP as effectively as EDCA does. In summary, for a wireless network that needs to support VoIP applications with minimal latency and effective bandwidth management, Enhanced Distributed Channel Access (EDCA) is the most appropriate choice due to its ability to prioritize voice traffic and ensure a high-quality user experience.
Incorrect
On the other hand, Point Coordination Function (PCF) and Distributed Coordination Function (DCF) do not provide the same level of QoS management as EDCA. PCF is a polling-based protocol that can introduce delays, making it less suitable for real-time applications like VoIP. DCF, while it is the fundamental access method for wireless LANs, operates on a contention basis and does not prioritize traffic, which can lead to increased latency for time-sensitive applications. Hybrid Coordination Function (HCF) combines elements of both EDCA and PCF but is primarily focused on providing a balance between contention-based and contention-free access. However, it does not specifically enhance QoS for VoIP as effectively as EDCA does. In summary, for a wireless network that needs to support VoIP applications with minimal latency and effective bandwidth management, Enhanced Distributed Channel Access (EDCA) is the most appropriate choice due to its ability to prioritize voice traffic and ensure a high-quality user experience.
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Question 10 of 30
10. Question
In a multi-homed environment where a company is using BGP to connect to two different ISPs, the network administrator is tasked with optimizing outbound traffic. The administrator decides to manipulate BGP attributes to influence the path selection process. Given the following BGP attributes: Local Preference, AS Path, and MED, which combination of attributes should the administrator prioritize to ensure that traffic is primarily routed through the preferred ISP while still allowing for failover to the secondary ISP if the primary fails?
Correct
The Multi-Exit Discriminator (MED) is another attribute that can influence the selection of routes when multiple paths exist to reach the same destination from different ASes. A lower MED value is preferred, meaning that if the administrator sets a lower MED for the routes from the secondary ISP, it will be less attractive compared to the primary ISP’s routes, which have a higher Local Preference. The AS Path attribute is primarily used for inbound traffic control and is less effective for outbound traffic decisions in this scenario. While it can influence route selection, it is not as impactful as Local Preference and MED in determining the preferred exit point from the AS. Therefore, the optimal strategy is to increase the Local Preference for the preferred ISP’s routes, ensuring they are selected for outbound traffic, while setting a lower MED for the secondary ISP’s routes to maintain them as a backup option. This approach allows for efficient traffic management while providing a failover mechanism if the primary ISP becomes unavailable.
Incorrect
The Multi-Exit Discriminator (MED) is another attribute that can influence the selection of routes when multiple paths exist to reach the same destination from different ASes. A lower MED value is preferred, meaning that if the administrator sets a lower MED for the routes from the secondary ISP, it will be less attractive compared to the primary ISP’s routes, which have a higher Local Preference. The AS Path attribute is primarily used for inbound traffic control and is less effective for outbound traffic decisions in this scenario. While it can influence route selection, it is not as impactful as Local Preference and MED in determining the preferred exit point from the AS. Therefore, the optimal strategy is to increase the Local Preference for the preferred ISP’s routes, ensuring they are selected for outbound traffic, while setting a lower MED for the secondary ISP’s routes to maintain them as a backup option. This approach allows for efficient traffic management while providing a failover mechanism if the primary ISP becomes unavailable.
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Question 11 of 30
11. Question
In a network utilizing EIGRP, a network engineer is tasked with summarizing the routes for a set of subnets: 192.168.1.0/24, 192.168.2.0/24, and 192.168.3.0/24. The engineer needs to determine the most efficient summary address that can be advertised to reduce the size of the routing table. What is the correct summary address that should be used for these subnets?
Correct
– 192.168.1.0/24: 11000000.10101000.00000001.00000000 – 192.168.2.0/24: 11000000.10101000.00000010.00000000 – 192.168.3.0/24: 11000000.10101000.00000011.00000000 Next, we observe the binary representations to identify the common prefix. The first two octets (192.168) are identical across all three subnets. The third octet varies from 1 to 3, which in binary is: – 1: 00000001 – 2: 00000010 – 3: 00000011 The common bits in the third octet are the first 6 bits (000000), which means we can summarize these three subnets into a single address. The summary address will take the first two octets (192.168) and the first 6 bits of the third octet (000000), followed by the last 2 bits set to 0, resulting in the third octet being 00000000. Therefore, the summary address is 192.168.0.0. To determine the prefix length, we note that the first two octets contribute 16 bits, and the first 6 bits of the third octet contribute an additional 6 bits, leading to a total of 22 bits. Thus, the summarized address is 192.168.0.0/22. Using route summarization in EIGRP not only reduces the size of the routing table but also minimizes the amount of routing information exchanged between routers, which can enhance network performance and stability. This is particularly important in larger networks where numerous subnets can lead to excessive routing updates and increased processing overhead. Therefore, the correct summary address that should be advertised for the given subnets is 192.168.0.0/22.
Incorrect
– 192.168.1.0/24: 11000000.10101000.00000001.00000000 – 192.168.2.0/24: 11000000.10101000.00000010.00000000 – 192.168.3.0/24: 11000000.10101000.00000011.00000000 Next, we observe the binary representations to identify the common prefix. The first two octets (192.168) are identical across all three subnets. The third octet varies from 1 to 3, which in binary is: – 1: 00000001 – 2: 00000010 – 3: 00000011 The common bits in the third octet are the first 6 bits (000000), which means we can summarize these three subnets into a single address. The summary address will take the first two octets (192.168) and the first 6 bits of the third octet (000000), followed by the last 2 bits set to 0, resulting in the third octet being 00000000. Therefore, the summary address is 192.168.0.0. To determine the prefix length, we note that the first two octets contribute 16 bits, and the first 6 bits of the third octet contribute an additional 6 bits, leading to a total of 22 bits. Thus, the summarized address is 192.168.0.0/22. Using route summarization in EIGRP not only reduces the size of the routing table but also minimizes the amount of routing information exchanged between routers, which can enhance network performance and stability. This is particularly important in larger networks where numerous subnets can lead to excessive routing updates and increased processing overhead. Therefore, the correct summary address that should be advertised for the given subnets is 192.168.0.0/22.
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Question 12 of 30
12. Question
In a network utilizing EIGRP, a network engineer is tasked with summarizing the routes for a set of subnets: 192.168.1.0/24, 192.168.2.0/24, and 192.168.3.0/24. The engineer needs to determine the most efficient summary address that can be advertised to reduce the size of the routing table. What is the correct summary address that should be used for these subnets?
Correct
– 192.168.1.0/24: 11000000.10101000.00000001.00000000 – 192.168.2.0/24: 11000000.10101000.00000010.00000000 – 192.168.3.0/24: 11000000.10101000.00000011.00000000 Next, we observe the binary representations to identify the common prefix. The first two octets (192.168) are identical across all three subnets. The third octet varies from 1 to 3, which in binary is: – 1: 00000001 – 2: 00000010 – 3: 00000011 The common bits in the third octet are the first 6 bits (000000), which means we can summarize these three subnets into a single address. The summary address will take the first two octets (192.168) and the first 6 bits of the third octet (000000), followed by the last 2 bits set to 0, resulting in the third octet being 00000000. Therefore, the summary address is 192.168.0.0. To determine the prefix length, we note that the first two octets contribute 16 bits, and the first 6 bits of the third octet contribute an additional 6 bits, leading to a total of 22 bits. Thus, the summarized address is 192.168.0.0/22. Using route summarization in EIGRP not only reduces the size of the routing table but also minimizes the amount of routing information exchanged between routers, which can enhance network performance and stability. This is particularly important in larger networks where numerous subnets can lead to excessive routing updates and increased processing overhead. Therefore, the correct summary address that should be advertised for the given subnets is 192.168.0.0/22.
Incorrect
– 192.168.1.0/24: 11000000.10101000.00000001.00000000 – 192.168.2.0/24: 11000000.10101000.00000010.00000000 – 192.168.3.0/24: 11000000.10101000.00000011.00000000 Next, we observe the binary representations to identify the common prefix. The first two octets (192.168) are identical across all three subnets. The third octet varies from 1 to 3, which in binary is: – 1: 00000001 – 2: 00000010 – 3: 00000011 The common bits in the third octet are the first 6 bits (000000), which means we can summarize these three subnets into a single address. The summary address will take the first two octets (192.168) and the first 6 bits of the third octet (000000), followed by the last 2 bits set to 0, resulting in the third octet being 00000000. Therefore, the summary address is 192.168.0.0. To determine the prefix length, we note that the first two octets contribute 16 bits, and the first 6 bits of the third octet contribute an additional 6 bits, leading to a total of 22 bits. Thus, the summarized address is 192.168.0.0/22. Using route summarization in EIGRP not only reduces the size of the routing table but also minimizes the amount of routing information exchanged between routers, which can enhance network performance and stability. This is particularly important in larger networks where numerous subnets can lead to excessive routing updates and increased processing overhead. Therefore, the correct summary address that should be advertised for the given subnets is 192.168.0.0/22.
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Question 13 of 30
13. Question
In a service provider network utilizing MPLS, a network engineer is tasked with configuring a new MPLS label-switched path (LSP) between two routers, R1 and R2. The engineer needs to ensure that the LSP can handle a traffic load of 10 Mbps and is required to implement a traffic engineering solution that allows for dynamic bandwidth allocation. Given that the maximum label stack depth is 3 and the MPLS header adds 4 bytes per label, what is the minimum MTU size that must be configured on the interfaces of R1 and R2 to accommodate the MPLS headers and the expected traffic load?
Correct
\[ \text{Total MPLS Overhead} = \text{Number of Labels} \times \text{Size of Each Label} = 3 \times 4 \text{ bytes} = 12 \text{ bytes} \] Next, we need to account for the standard Ethernet frame overhead, which includes the Ethernet header (14 bytes) and the Frame Check Sequence (FCS) (4 bytes). Therefore, the total overhead for an Ethernet frame is: \[ \text{Ethernet Overhead} = 14 \text{ bytes} + 4 \text{ bytes} = 18 \text{ bytes} \] Now, to calculate the minimum MTU size, we must add the payload size (10 Mbps) converted to bytes per second, which is: \[ \text{Payload Size} = 10 \text{ Mbps} = \frac{10 \times 10^6 \text{ bits}}{8} = 1,250,000 \text{ bytes per second} \] However, since we are calculating the MTU for a single packet, we need to consider the typical size of a packet. For example, if we assume a standard packet size of 1500 bytes (which is common for Ethernet), we can calculate the required MTU as follows: \[ \text{MTU} = \text{Payload Size} + \text{Total MPLS Overhead} + \text{Ethernet Overhead} = 1500 + 12 + 18 = 1530 \text{ bytes} \] Since the MTU must be greater than or equal to this value, the minimum MTU size that must be configured on the interfaces of R1 and R2 to accommodate the MPLS headers and the expected traffic load is 1600 bytes. This ensures that the network can handle the MPLS overhead while still allowing for efficient data transmission without fragmentation. Thus, the correct answer is 1600 bytes, which is the only option that meets the requirements for the MPLS configuration in this scenario.
Incorrect
\[ \text{Total MPLS Overhead} = \text{Number of Labels} \times \text{Size of Each Label} = 3 \times 4 \text{ bytes} = 12 \text{ bytes} \] Next, we need to account for the standard Ethernet frame overhead, which includes the Ethernet header (14 bytes) and the Frame Check Sequence (FCS) (4 bytes). Therefore, the total overhead for an Ethernet frame is: \[ \text{Ethernet Overhead} = 14 \text{ bytes} + 4 \text{ bytes} = 18 \text{ bytes} \] Now, to calculate the minimum MTU size, we must add the payload size (10 Mbps) converted to bytes per second, which is: \[ \text{Payload Size} = 10 \text{ Mbps} = \frac{10 \times 10^6 \text{ bits}}{8} = 1,250,000 \text{ bytes per second} \] However, since we are calculating the MTU for a single packet, we need to consider the typical size of a packet. For example, if we assume a standard packet size of 1500 bytes (which is common for Ethernet), we can calculate the required MTU as follows: \[ \text{MTU} = \text{Payload Size} + \text{Total MPLS Overhead} + \text{Ethernet Overhead} = 1500 + 12 + 18 = 1530 \text{ bytes} \] Since the MTU must be greater than or equal to this value, the minimum MTU size that must be configured on the interfaces of R1 and R2 to accommodate the MPLS headers and the expected traffic load is 1600 bytes. This ensures that the network can handle the MPLS overhead while still allowing for efficient data transmission without fragmentation. Thus, the correct answer is 1600 bytes, which is the only option that meets the requirements for the MPLS configuration in this scenario.
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Question 14 of 30
14. Question
In a corporate network, a DHCP server is configured to provide IP addresses to clients within the range of 192.168.1.10 to 192.168.1.100. However, users are reporting that they are unable to obtain an IP address from the DHCP server. Upon investigation, you find that the DHCP server is operational, and the network interface is up. Additionally, you notice that the DHCP lease time is set to 24 hours. What could be the most likely reason for the clients not receiving an IP address, and how would you approach troubleshooting this issue?
Correct
To troubleshoot this, first, check the DHCP server’s lease database to determine how many leases are currently active. If the number of active leases is equal to or exceeds the configured range (in this case, 192.168.1.10 to 192.168.1.100), the server cannot assign new IP addresses until some leases expire or are released. Next, consider the lease time, which is set to 24 hours. If many devices frequently connect and disconnect from the network, the lease time may need to be adjusted to a shorter duration to free up IP addresses more quickly. While options such as incorrect default gateway configuration, firewall issues, or static IP conflicts could also lead to connectivity problems, they do not directly explain the inability to obtain an IP address from the DHCP server. Therefore, focusing on the DHCP scope and lease management is crucial in resolving this issue. In summary, understanding the dynamics of DHCP lease allocation and the implications of scope exhaustion is essential for effective troubleshooting in a network environment.
Incorrect
To troubleshoot this, first, check the DHCP server’s lease database to determine how many leases are currently active. If the number of active leases is equal to or exceeds the configured range (in this case, 192.168.1.10 to 192.168.1.100), the server cannot assign new IP addresses until some leases expire or are released. Next, consider the lease time, which is set to 24 hours. If many devices frequently connect and disconnect from the network, the lease time may need to be adjusted to a shorter duration to free up IP addresses more quickly. While options such as incorrect default gateway configuration, firewall issues, or static IP conflicts could also lead to connectivity problems, they do not directly explain the inability to obtain an IP address from the DHCP server. Therefore, focusing on the DHCP scope and lease management is crucial in resolving this issue. In summary, understanding the dynamics of DHCP lease allocation and the implications of scope exhaustion is essential for effective troubleshooting in a network environment.
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Question 15 of 30
15. Question
In a corporate network, a network engineer is tasked with implementing a secure routing protocol to ensure the confidentiality and integrity of routing updates. The engineer considers using protocols such as OSPFv3 with IPsec, EIGRP with MD5 authentication, and BGP with TCP MD5 signatures. Given the need for both authentication and encryption of routing information, which combination of protocols and features would best meet the security requirements while maintaining efficient routing performance?
Correct
On the other hand, EIGRP with MD5 authentication provides a level of integrity by ensuring that routing updates are from a trusted source, but it does not offer encryption. This means that while the updates are authenticated, they can still be intercepted and read by unauthorized parties, which does not meet the requirement for confidentiality. BGP with TCP MD5 signatures also provides authentication for BGP sessions, ensuring that the peers are legitimate. However, like EIGRP with MD5, it lacks encryption capabilities, leaving the routing information vulnerable to interception. Lastly, OSPFv2 with plaintext authentication is the least secure option, as it does not provide any encryption or strong authentication, making it susceptible to various attacks, including replay attacks and man-in-the-middle attacks. In summary, the best choice for ensuring both the confidentiality and integrity of routing updates in this scenario is OSPFv3 with IPsec, as it effectively combines encryption and authentication, thereby meeting the security requirements while maintaining efficient routing performance.
Incorrect
On the other hand, EIGRP with MD5 authentication provides a level of integrity by ensuring that routing updates are from a trusted source, but it does not offer encryption. This means that while the updates are authenticated, they can still be intercepted and read by unauthorized parties, which does not meet the requirement for confidentiality. BGP with TCP MD5 signatures also provides authentication for BGP sessions, ensuring that the peers are legitimate. However, like EIGRP with MD5, it lacks encryption capabilities, leaving the routing information vulnerable to interception. Lastly, OSPFv2 with plaintext authentication is the least secure option, as it does not provide any encryption or strong authentication, making it susceptible to various attacks, including replay attacks and man-in-the-middle attacks. In summary, the best choice for ensuring both the confidentiality and integrity of routing updates in this scenario is OSPFv3 with IPsec, as it effectively combines encryption and authentication, thereby meeting the security requirements while maintaining efficient routing performance.
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Question 16 of 30
16. Question
In a network utilizing Segment Routing (SR), a service provider is tasked with configuring a Segment Routing Traffic Engineering (SR-TE) policy to optimize the path for a specific application that requires low latency and high bandwidth. The provider has multiple paths available, each with different metrics. The metrics for the paths are as follows: Path A has a latency of 10 ms and a bandwidth of 100 Mbps, Path B has a latency of 15 ms and a bandwidth of 150 Mbps, Path C has a latency of 5 ms and a bandwidth of 50 Mbps, and Path D has a latency of 20 ms and a bandwidth of 200 Mbps. Given that the application is highly sensitive to latency, which path should be selected for the SR-TE policy to ensure optimal performance?
Correct
To evaluate the paths, we first look at the latency values. Path C has the lowest latency at 5 ms, making it the most suitable choice for applications sensitive to latency. Although Path C has a bandwidth of 50 Mbps, which is lower than the other paths, the critical factor here is the latency requirement. Next, we analyze the other paths: – Path A has a latency of 10 ms and a bandwidth of 100 Mbps. While it offers a higher bandwidth, the increased latency makes it less optimal for the application. – Path B has a latency of 15 ms and a bandwidth of 150 Mbps. Again, while the bandwidth is appealing, the latency is significantly higher than Path C. – Path D has the highest latency at 20 ms, despite having the highest bandwidth of 200 Mbps. This path is clearly unsuitable for the latency-sensitive application. In Segment Routing, the ability to prioritize paths based on specific metrics allows network operators to make informed decisions. In this case, the decision to select Path C is justified by its superior latency performance, even though it has lower bandwidth compared to other options. This highlights the importance of understanding the trade-offs between latency and bandwidth in SR-TE configurations, ensuring that the chosen path aligns with the application’s performance requirements. Thus, the optimal path for the SR-TE policy is Path C, as it best meets the application’s need for low latency.
Incorrect
To evaluate the paths, we first look at the latency values. Path C has the lowest latency at 5 ms, making it the most suitable choice for applications sensitive to latency. Although Path C has a bandwidth of 50 Mbps, which is lower than the other paths, the critical factor here is the latency requirement. Next, we analyze the other paths: – Path A has a latency of 10 ms and a bandwidth of 100 Mbps. While it offers a higher bandwidth, the increased latency makes it less optimal for the application. – Path B has a latency of 15 ms and a bandwidth of 150 Mbps. Again, while the bandwidth is appealing, the latency is significantly higher than Path C. – Path D has the highest latency at 20 ms, despite having the highest bandwidth of 200 Mbps. This path is clearly unsuitable for the latency-sensitive application. In Segment Routing, the ability to prioritize paths based on specific metrics allows network operators to make informed decisions. In this case, the decision to select Path C is justified by its superior latency performance, even though it has lower bandwidth compared to other options. This highlights the importance of understanding the trade-offs between latency and bandwidth in SR-TE configurations, ensuring that the chosen path aligns with the application’s performance requirements. Thus, the optimal path for the SR-TE policy is Path C, as it best meets the application’s need for low latency.
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Question 17 of 30
17. Question
A network engineer is troubleshooting a connectivity issue in a corporate environment where multiple VLANs are configured on a Layer 2 switch. The engineer notices that devices in VLAN 10 can communicate with each other but cannot reach devices in VLAN 20. The switch is configured with inter-VLAN routing enabled on a router connected to the switch. What could be the most likely cause of this issue?
Correct
The most plausible explanation for the connectivity issue is that the router’s subinterface for VLAN 20 is not configured correctly. Each VLAN requires a corresponding subinterface on the router to handle traffic for that VLAN. If the subinterface for VLAN 20 is missing, misconfigured, or down, devices in VLAN 10 will not be able to communicate with devices in VLAN 20, as there is no routing path established for that VLAN. Option b suggests that the switch is not allowing VLAN 20 traffic to pass through, which is less likely if VLAN 20 is configured on the switch and the switch ports are correctly assigned to the VLAN. Option c, which states that devices in VLAN 20 are using incorrect IP addresses, could be a contributing factor, but it does not explain why VLAN 10 devices cannot reach them; it would only affect communication from VLAN 20 to other networks. Lastly, option d implies that the switch’s trunk port is misconfigured to only allow VLAN 10, which would prevent VLAN 20 traffic from reaching the router, but if VLAN 20 is configured on the switch and the trunk is set up correctly, this should not be the case. In summary, the troubleshooting process should focus on verifying the router’s subinterface configuration for VLAN 20, ensuring it is correctly set up with the appropriate IP address and that it is operational. Additionally, checking the switch’s VLAN configuration and trunk settings can help confirm that VLAN 20 traffic is being correctly forwarded to the router for inter-VLAN routing.
Incorrect
The most plausible explanation for the connectivity issue is that the router’s subinterface for VLAN 20 is not configured correctly. Each VLAN requires a corresponding subinterface on the router to handle traffic for that VLAN. If the subinterface for VLAN 20 is missing, misconfigured, or down, devices in VLAN 10 will not be able to communicate with devices in VLAN 20, as there is no routing path established for that VLAN. Option b suggests that the switch is not allowing VLAN 20 traffic to pass through, which is less likely if VLAN 20 is configured on the switch and the switch ports are correctly assigned to the VLAN. Option c, which states that devices in VLAN 20 are using incorrect IP addresses, could be a contributing factor, but it does not explain why VLAN 10 devices cannot reach them; it would only affect communication from VLAN 20 to other networks. Lastly, option d implies that the switch’s trunk port is misconfigured to only allow VLAN 10, which would prevent VLAN 20 traffic from reaching the router, but if VLAN 20 is configured on the switch and the trunk is set up correctly, this should not be the case. In summary, the troubleshooting process should focus on verifying the router’s subinterface configuration for VLAN 20, ensuring it is correctly set up with the appropriate IP address and that it is operational. Additionally, checking the switch’s VLAN configuration and trunk settings can help confirm that VLAN 20 traffic is being correctly forwarded to the router for inter-VLAN routing.
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Question 18 of 30
18. Question
In a corporate network, a security analyst is tasked with mitigating threats from potential Distributed Denial of Service (DDoS) attacks. The network architecture includes multiple layers of defense, such as firewalls, intrusion prevention systems (IPS), and rate limiting on routers. The analyst needs to determine the most effective combination of strategies to ensure the availability of critical services while minimizing the impact of such attacks. Which approach should the analyst prioritize to enhance the network’s resilience against DDoS attacks?
Correct
Traffic filtering complements rate limiting by identifying and blocking malicious traffic patterns before they reach the internal network. This proactive measure reduces the load on internal resources and enhances overall network performance during an attack. Increasing bandwidth, while it may seem beneficial, does not address the underlying issue of malicious traffic and can lead to higher costs without guaranteeing improved security. Simply adding more firewalls may create complexity without effectively addressing the DDoS threat, as attackers can still overwhelm the network if the traffic is not managed at the entry point. Relying solely on an IPS is insufficient, as IPS systems are primarily designed for detecting and responding to known threats rather than managing high volumes of traffic typical in DDoS scenarios. In summary, the most effective strategy combines rate limiting and traffic filtering at the network’s edge, ensuring that the network can withstand and respond to DDoS attacks while maintaining service availability for legitimate users. This approach aligns with best practices in threat mitigation, emphasizing the importance of proactive measures in network security.
Incorrect
Traffic filtering complements rate limiting by identifying and blocking malicious traffic patterns before they reach the internal network. This proactive measure reduces the load on internal resources and enhances overall network performance during an attack. Increasing bandwidth, while it may seem beneficial, does not address the underlying issue of malicious traffic and can lead to higher costs without guaranteeing improved security. Simply adding more firewalls may create complexity without effectively addressing the DDoS threat, as attackers can still overwhelm the network if the traffic is not managed at the entry point. Relying solely on an IPS is insufficient, as IPS systems are primarily designed for detecting and responding to known threats rather than managing high volumes of traffic typical in DDoS scenarios. In summary, the most effective strategy combines rate limiting and traffic filtering at the network’s edge, ensuring that the network can withstand and respond to DDoS attacks while maintaining service availability for legitimate users. This approach aligns with best practices in threat mitigation, emphasizing the importance of proactive measures in network security.
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Question 19 of 30
19. Question
In a wireless network utilizing OSPF (Open Shortest Path First) for routing, a network engineer is tasked with optimizing the OSPF configuration to ensure efficient routing between multiple access points (APs) in a large enterprise environment. The engineer needs to consider the impact of OSPF area design on the overall network performance. Given that the network consists of three areas: Area 0 (backbone), Area 1, and Area 2, with Area 1 having a higher number of routers and links, what is the most effective strategy for configuring OSPF to minimize routing overhead and improve convergence times across the wireless network?
Correct
This configuration is particularly beneficial in a scenario where Area 1 has a higher number of routers and links, as it helps to limit the complexity of the routing topology. The routers in Area 1 will only need to maintain routes to the backbone (Area 0) and the default route to reach external networks, thus improving convergence times and reducing the processing load on the routers. In contrast, configuring all areas as totally stubby areas (option b) would overly restrict routing information and could lead to suboptimal routing paths, as routers would only have access to a default route. Using OSPF virtual links (option c) can introduce additional complexity and potential instability in the network, especially in a wireless environment where mobility and dynamic changes are common. Lastly, increasing the OSPF hello and dead intervals (option d) would actually delay the detection of neighbor failures, leading to slower convergence times, which is counterproductive in a dynamic wireless network. Overall, the best approach is to implement a hierarchical OSPF design with stub areas to effectively manage routing overhead and enhance the performance of the wireless network.
Incorrect
This configuration is particularly beneficial in a scenario where Area 1 has a higher number of routers and links, as it helps to limit the complexity of the routing topology. The routers in Area 1 will only need to maintain routes to the backbone (Area 0) and the default route to reach external networks, thus improving convergence times and reducing the processing load on the routers. In contrast, configuring all areas as totally stubby areas (option b) would overly restrict routing information and could lead to suboptimal routing paths, as routers would only have access to a default route. Using OSPF virtual links (option c) can introduce additional complexity and potential instability in the network, especially in a wireless environment where mobility and dynamic changes are common. Lastly, increasing the OSPF hello and dead intervals (option d) would actually delay the detection of neighbor failures, leading to slower convergence times, which is counterproductive in a dynamic wireless network. Overall, the best approach is to implement a hierarchical OSPF design with stub areas to effectively manage routing overhead and enhance the performance of the wireless network.
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Question 20 of 30
20. Question
In a corporate network, a network engineer is tasked with implementing Quality of Service (QoS) to prioritize voice traffic over regular data traffic. The engineer decides to use Differentiated Services Code Point (DSCP) values to classify and mark packets. Given that voice traffic is assigned a DSCP value of 46 (EF – Expedited Forwarding), and the total bandwidth of the link is 1 Gbps, how much bandwidth should be allocated to voice traffic if the engineer wants to ensure that voice packets receive a minimum of 30% of the total bandwidth during peak usage times?
Correct
To calculate the required bandwidth for voice traffic, we can use the formula: \[ \text{Allocated Bandwidth} = \text{Total Bandwidth} \times \text{Percentage Allocation} \] Substituting the values into the formula gives: \[ \text{Allocated Bandwidth} = 1000 \text{ Mbps} \times 0.30 = 300 \text{ Mbps} \] This calculation indicates that to meet the requirement of prioritizing voice traffic, the network engineer should allocate 300 Mbps specifically for voice packets. The other options represent common misconceptions regarding bandwidth allocation. For instance, 150 Mbps (option b) would not meet the 30% requirement, as it only accounts for 15% of the total bandwidth. Similarly, 400 Mbps (option c) exceeds the required allocation, which could lead to inefficient use of bandwidth for other types of traffic. Lastly, 200 Mbps (option d) also falls short of the necessary allocation, providing only 20% of the total bandwidth. In conclusion, understanding how to allocate bandwidth effectively using QoS principles is crucial for maintaining the performance of critical applications like voice over IP (VoIP). The use of DSCP values to classify traffic ensures that voice packets are prioritized, thus enhancing the overall user experience during peak times.
Incorrect
To calculate the required bandwidth for voice traffic, we can use the formula: \[ \text{Allocated Bandwidth} = \text{Total Bandwidth} \times \text{Percentage Allocation} \] Substituting the values into the formula gives: \[ \text{Allocated Bandwidth} = 1000 \text{ Mbps} \times 0.30 = 300 \text{ Mbps} \] This calculation indicates that to meet the requirement of prioritizing voice traffic, the network engineer should allocate 300 Mbps specifically for voice packets. The other options represent common misconceptions regarding bandwidth allocation. For instance, 150 Mbps (option b) would not meet the 30% requirement, as it only accounts for 15% of the total bandwidth. Similarly, 400 Mbps (option c) exceeds the required allocation, which could lead to inefficient use of bandwidth for other types of traffic. Lastly, 200 Mbps (option d) also falls short of the necessary allocation, providing only 20% of the total bandwidth. In conclusion, understanding how to allocate bandwidth effectively using QoS principles is crucial for maintaining the performance of critical applications like voice over IP (VoIP). The use of DSCP values to classify traffic ensures that voice packets are prioritized, thus enhancing the overall user experience during peak times.
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Question 21 of 30
21. Question
In a large enterprise network utilizing OSPF, a network engineer is tasked with optimizing the OSPF routing process to ensure efficient route selection and minimize convergence time. The engineer decides to implement OSPF area types strategically. Given the following OSPF area configurations: Area 0 (backbone area), Area 1 (standard area), and Area 2 (stub area), which configuration would best reduce the size of the OSPF routing table while maintaining connectivity to external networks?
Correct
On the other hand, configuring Area 1 as a totally stubby area would also reduce the routing table size, but it would not allow any external routes to be advertised, which may not be suitable if connectivity to external networks is required. Configuring Area 0 as a stub area is not valid since the backbone area must always be a standard area to maintain OSPF’s hierarchical structure. Lastly, configuring Area 1 as a not-so-stubby area (NSSA) allows for the injection of external routes but does not significantly reduce the routing table size compared to a stub area. In summary, the best approach to reduce the routing table size while maintaining necessary connectivity is to configure Area 2 as a stub area, as it effectively limits the routing information exchanged within that area without compromising the overall network connectivity. This strategic use of OSPF area types is essential for optimizing routing performance in large enterprise networks.
Incorrect
On the other hand, configuring Area 1 as a totally stubby area would also reduce the routing table size, but it would not allow any external routes to be advertised, which may not be suitable if connectivity to external networks is required. Configuring Area 0 as a stub area is not valid since the backbone area must always be a standard area to maintain OSPF’s hierarchical structure. Lastly, configuring Area 1 as a not-so-stubby area (NSSA) allows for the injection of external routes but does not significantly reduce the routing table size compared to a stub area. In summary, the best approach to reduce the routing table size while maintaining necessary connectivity is to configure Area 2 as a stub area, as it effectively limits the routing information exchanged within that area without compromising the overall network connectivity. This strategic use of OSPF area types is essential for optimizing routing performance in large enterprise networks.
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Question 22 of 30
22. Question
In a network automation scenario, a network engineer is tasked with developing an API that interacts with a Cisco router to retrieve interface statistics. The engineer needs to ensure that the API adheres to RESTful principles and provides a JSON response. Given the following requirements: the API should support GET requests to retrieve data, the response must include the interface name, status, and traffic statistics (input and output bytes), and it should be secured using OAuth 2.0. Which of the following best describes the key considerations the engineer must take into account when designing this API?
Correct
In this scenario, the requirement for a JSON response aligns with modern web application standards, as JSON is lightweight and easily parsed by JavaScript, making it ideal for web-based clients. The use of OAuth 2.0 for securing the API is also a best practice, as it provides a robust framework for authorization without exposing user credentials. The other options present misconceptions about API design. Maintaining session state can lead to scalability issues and is contrary to REST principles. While XML can be used, JSON is generally preferred for new applications. Complex authentication mechanisms can hinder usability and performance, and allowing both GET and POST requests without clear separation of concerns can lead to confusion and misuse of the API. Thus, the key considerations revolve around statelessness, proper use of HTTP methods and status codes, and the choice of response format.
Incorrect
In this scenario, the requirement for a JSON response aligns with modern web application standards, as JSON is lightweight and easily parsed by JavaScript, making it ideal for web-based clients. The use of OAuth 2.0 for securing the API is also a best practice, as it provides a robust framework for authorization without exposing user credentials. The other options present misconceptions about API design. Maintaining session state can lead to scalability issues and is contrary to REST principles. While XML can be used, JSON is generally preferred for new applications. Complex authentication mechanisms can hinder usability and performance, and allowing both GET and POST requests without clear separation of concerns can lead to confusion and misuse of the API. Thus, the key considerations revolve around statelessness, proper use of HTTP methods and status codes, and the choice of response format.
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Question 23 of 30
23. Question
In a large enterprise network, a network engineer is tasked with designing a scalable routing architecture that can accommodate future growth without significant reconfiguration. The current network consists of multiple branch offices connected to a central data center, and the engineer is considering implementing a routing protocol that can efficiently manage the increasing number of routes. Which routing protocol would best support the scalability requirements of this network while minimizing the overhead associated with route updates?
Correct
RIP, while simple to configure, has significant limitations in terms of scalability. It supports a maximum of 15 hops, which can be restrictive in larger networks. Additionally, RIP’s periodic updates can lead to unnecessary bandwidth consumption, especially as the network grows. EIGRP, although more scalable than RIP, is a Cisco proprietary protocol and may not be suitable for multi-vendor environments. It uses a hybrid approach, combining features of both distance-vector and link-state protocols, but it can still introduce complexity in larger networks due to its reliance on Diffusing Update Algorithm (DUAL) for route calculations. BGP, while highly scalable and suitable for inter-domain routing, is typically used in scenarios involving multiple autonomous systems and is not ideal for internal routing within a single enterprise network. Its complexity and configuration overhead make it less desirable for a straightforward internal routing solution. In summary, OSPF’s ability to segment the network into areas, reducing the size of the routing table and the frequency of updates, makes it the most suitable choice for a scalable routing architecture in a growing enterprise environment. This design allows for efficient management of routes and minimizes the impact of network changes, ensuring that the routing infrastructure can adapt to future growth without significant reconfiguration.
Incorrect
RIP, while simple to configure, has significant limitations in terms of scalability. It supports a maximum of 15 hops, which can be restrictive in larger networks. Additionally, RIP’s periodic updates can lead to unnecessary bandwidth consumption, especially as the network grows. EIGRP, although more scalable than RIP, is a Cisco proprietary protocol and may not be suitable for multi-vendor environments. It uses a hybrid approach, combining features of both distance-vector and link-state protocols, but it can still introduce complexity in larger networks due to its reliance on Diffusing Update Algorithm (DUAL) for route calculations. BGP, while highly scalable and suitable for inter-domain routing, is typically used in scenarios involving multiple autonomous systems and is not ideal for internal routing within a single enterprise network. Its complexity and configuration overhead make it less desirable for a straightforward internal routing solution. In summary, OSPF’s ability to segment the network into areas, reducing the size of the routing table and the frequency of updates, makes it the most suitable choice for a scalable routing architecture in a growing enterprise environment. This design allows for efficient management of routes and minimizes the impact of network changes, ensuring that the routing infrastructure can adapt to future growth without significant reconfiguration.
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Question 24 of 30
24. Question
In a network utilizing OSPFv2, a router is configured with multiple OSPF areas, including Area 0 (the backbone area) and Area 1. If a new router is added to Area 1 and is configured to establish OSPF adjacency with the existing routers in that area, what must be ensured for the OSPF routing protocol to function correctly across these areas, particularly in terms of LSA types and their propagation?
Correct
If the new router has a different area ID, it will not be able to form adjacencies with the existing routers, and thus, it will not receive or send LSAs, leading to routing inconsistencies. The designated router (DR) and backup designated router (BDR) roles are determined by OSPF priority, but this is secondary to the requirement of matching area IDs for adjacency formation. Furthermore, OSPFv2 and OSPFv3 are not directly interchangeable; OSPFv3 is designed for IPv6 networks, while OSPFv2 is used for IPv4. Therefore, configuring the new router to use OSPFv3 would not be appropriate in an IPv4 environment. Lastly, while connecting to Area 0 (the backbone area) is essential for inter-area routing, it is not a requirement for routers within the same non-backbone area to exchange LSAs. Thus, ensuring the correct area ID configuration is the primary requirement for the new router to function correctly within Area 1.
Incorrect
If the new router has a different area ID, it will not be able to form adjacencies with the existing routers, and thus, it will not receive or send LSAs, leading to routing inconsistencies. The designated router (DR) and backup designated router (BDR) roles are determined by OSPF priority, but this is secondary to the requirement of matching area IDs for adjacency formation. Furthermore, OSPFv2 and OSPFv3 are not directly interchangeable; OSPFv3 is designed for IPv6 networks, while OSPFv2 is used for IPv4. Therefore, configuring the new router to use OSPFv3 would not be appropriate in an IPv4 environment. Lastly, while connecting to Area 0 (the backbone area) is essential for inter-area routing, it is not a requirement for routers within the same non-backbone area to exchange LSAs. Thus, ensuring the correct area ID configuration is the primary requirement for the new router to function correctly within Area 1.
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Question 25 of 30
25. Question
In a wireless network utilizing EIGRP for Wireless, a network administrator is tasked with optimizing the routing performance for a set of access points (APs) that are experiencing high latency and packet loss. The administrator decides to implement EIGRP’s unequal-cost load balancing feature. Given that the bandwidth of the primary link is 10 Mbps and the secondary link is 5 Mbps, how should the administrator configure the variance to ensure that traffic is effectively distributed across both links while adhering to EIGRP’s metrics? Assume the delay for the primary link is 10 ms and for the secondary link is 20 ms.
Correct
$$ Metric = \left( \frac{10^7}{Bandwidth} + Delay \right) \times 256 $$ For the primary link with a bandwidth of 10 Mbps and a delay of 10 ms, the metric calculation is as follows: $$ Metric_{primary} = \left( \frac{10^7}{10 \times 10^6} + 10 \right) \times 256 = \left( 1 + 10 \right) \times 256 = 11 \times 256 = 2816 $$ For the secondary link with a bandwidth of 5 Mbps and a delay of 20 ms, the metric is calculated as: $$ Metric_{secondary} = \left( \frac{10^7}{5 \times 10^6} + 20 \right) \times 256 = \left( 2 + 20 \right) \times 256 = 22 \times 256 = 5632 $$ To enable unequal-cost load balancing, the administrator must set the variance to a value that allows the secondary link’s metric to be considered for routing. The variance is a multiplier applied to the best metric to determine which routes are eligible for load balancing. In this case, the best metric is 2816 (from the primary link). To find the maximum allowable metric for the secondary link, we calculate: $$ Max_{allowed} = Variance \times Metric_{best} $$ To include the secondary link in the routing table, we need: $$ 5632 \leq Variance \times 2816 $$ Solving for variance gives: $$ Variance \geq \frac{5632}{2816} = 2 $$ Thus, the minimum variance that allows the secondary link to be utilized for load balancing is 2. Setting the variance to 2 will enable the EIGRP to consider both links for routing, effectively distributing the traffic and optimizing performance. Therefore, the correct configuration for the variance is to set it to 2, allowing for effective load balancing across both links while adhering to EIGRP’s operational principles.
Incorrect
$$ Metric = \left( \frac{10^7}{Bandwidth} + Delay \right) \times 256 $$ For the primary link with a bandwidth of 10 Mbps and a delay of 10 ms, the metric calculation is as follows: $$ Metric_{primary} = \left( \frac{10^7}{10 \times 10^6} + 10 \right) \times 256 = \left( 1 + 10 \right) \times 256 = 11 \times 256 = 2816 $$ For the secondary link with a bandwidth of 5 Mbps and a delay of 20 ms, the metric is calculated as: $$ Metric_{secondary} = \left( \frac{10^7}{5 \times 10^6} + 20 \right) \times 256 = \left( 2 + 20 \right) \times 256 = 22 \times 256 = 5632 $$ To enable unequal-cost load balancing, the administrator must set the variance to a value that allows the secondary link’s metric to be considered for routing. The variance is a multiplier applied to the best metric to determine which routes are eligible for load balancing. In this case, the best metric is 2816 (from the primary link). To find the maximum allowable metric for the secondary link, we calculate: $$ Max_{allowed} = Variance \times Metric_{best} $$ To include the secondary link in the routing table, we need: $$ 5632 \leq Variance \times 2816 $$ Solving for variance gives: $$ Variance \geq \frac{5632}{2816} = 2 $$ Thus, the minimum variance that allows the secondary link to be utilized for load balancing is 2. Setting the variance to 2 will enable the EIGRP to consider both links for routing, effectively distributing the traffic and optimizing performance. Therefore, the correct configuration for the variance is to set it to 2, allowing for effective load balancing across both links while adhering to EIGRP’s operational principles.
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Question 26 of 30
26. Question
In a corporate network, a network engineer is troubleshooting Quality of Service (QoS) issues that are affecting VoIP call quality. The engineer notices that the jitter buffer is consistently exceeding the configured threshold of 30 ms, leading to dropped calls and poor audio quality. The network is configured with multiple classes of service, and the engineer is tasked with determining the best approach to optimize the QoS settings. Given the current configuration, which of the following actions should the engineer prioritize to effectively reduce jitter and improve VoIP performance?
Correct
On the other hand, decreasing the MTU size for all traffic classes may lead to increased overhead and fragmentation, which can exacerbate jitter rather than alleviate it. While a stricter policing mechanism could limit bandwidth usage, it may inadvertently restrict the necessary bandwidth for VoIP, leading to further degradation of call quality. Lastly, enabling random early detection (RED) can help manage congestion but is not a direct solution to the jitter issue; it primarily addresses packet loss rather than jitter itself. In summary, prioritizing VoIP traffic in the QoS policy is the most effective strategy to mitigate jitter and enhance overall call quality, as it directly addresses the needs of time-sensitive applications like VoIP. This approach aligns with QoS principles, which emphasize the importance of traffic classification and prioritization to ensure optimal performance for critical applications.
Incorrect
On the other hand, decreasing the MTU size for all traffic classes may lead to increased overhead and fragmentation, which can exacerbate jitter rather than alleviate it. While a stricter policing mechanism could limit bandwidth usage, it may inadvertently restrict the necessary bandwidth for VoIP, leading to further degradation of call quality. Lastly, enabling random early detection (RED) can help manage congestion but is not a direct solution to the jitter issue; it primarily addresses packet loss rather than jitter itself. In summary, prioritizing VoIP traffic in the QoS policy is the most effective strategy to mitigate jitter and enhance overall call quality, as it directly addresses the needs of time-sensitive applications like VoIP. This approach aligns with QoS principles, which emphasize the importance of traffic classification and prioritization to ensure optimal performance for critical applications.
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Question 27 of 30
27. Question
In a corporate environment, a network engineer is tasked with designing a secure site-to-site VPN between two branch offices located in different geographical regions. The engineer decides to implement an IPsec VPN using IKEv2 for key exchange. Given that the branch offices have different internal IP address ranges (Office A: 192.168.1.0/24 and Office B: 10.1.1.0/24), what must the engineer ensure regarding the configuration of the VPN to facilitate seamless communication between the two sites?
Correct
One of the key aspects of the VPN configuration is the establishment of static routes that direct traffic from one internal network to the other. This means that the engineer must configure the routers at both sites to recognize the remote network. For example, Office A’s router must have a static route pointing to the 10.1.1.0/24 network via the VPN tunnel, and vice versa for Office B. This routing ensures that packets destined for the remote site are correctly forwarded through the VPN. While NAT traversal is a consideration in scenarios where overlapping IP addresses exist, it is not necessary in this case since the IP ranges are distinct. GRE encapsulation is not required unless there is a need to support multicast or non-IP traffic, which is not indicated in the scenario. Lastly, while SSL can provide encryption, it is not the standard for IPsec VPNs, which inherently provide encryption through their protocols. Thus, the correct approach involves ensuring that static routes are properly configured to facilitate communication between the two distinct internal networks over the established IPsec VPN. This understanding of routing and VPN configuration is essential for ensuring seamless connectivity in a multi-site corporate environment.
Incorrect
One of the key aspects of the VPN configuration is the establishment of static routes that direct traffic from one internal network to the other. This means that the engineer must configure the routers at both sites to recognize the remote network. For example, Office A’s router must have a static route pointing to the 10.1.1.0/24 network via the VPN tunnel, and vice versa for Office B. This routing ensures that packets destined for the remote site are correctly forwarded through the VPN. While NAT traversal is a consideration in scenarios where overlapping IP addresses exist, it is not necessary in this case since the IP ranges are distinct. GRE encapsulation is not required unless there is a need to support multicast or non-IP traffic, which is not indicated in the scenario. Lastly, while SSL can provide encryption, it is not the standard for IPsec VPNs, which inherently provide encryption through their protocols. Thus, the correct approach involves ensuring that static routes are properly configured to facilitate communication between the two distinct internal networks over the established IPsec VPN. This understanding of routing and VPN configuration is essential for ensuring seamless connectivity in a multi-site corporate environment.
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Question 28 of 30
28. Question
In a network utilizing Segment Routing (SR), you are tasked with configuring a Segment Routing Traffic Engineering (SR-TE) policy to optimize the path for a specific application that requires low latency. The application is sensitive to packet loss and jitter, and the network topology includes multiple paths with varying bandwidth and latency characteristics. Given the following parameters: Path A has a latency of 20 ms and a bandwidth of 100 Mbps, Path B has a latency of 15 ms and a bandwidth of 50 Mbps, and Path C has a latency of 25 ms and a bandwidth of 150 Mbps. Which path should be selected for the SR-TE policy to best meet the application’s requirements?
Correct
Path A has a latency of 20 ms and a bandwidth of 100 Mbps. While it offers a decent bandwidth, its latency is higher than that of Path B. Path B, with a latency of 15 ms, is the lowest latency option available, but it has a bandwidth of only 50 Mbps. This could potentially lead to congestion if the application requires more than 50 Mbps, which may not be suitable for high-demand scenarios. Path C, on the other hand, has a latency of 25 ms and a bandwidth of 150 Mbps. Although it provides the highest bandwidth, the increased latency makes it less desirable for an application that prioritizes low latency. Given the application’s sensitivity to latency, Path B emerges as the optimal choice despite its lower bandwidth. It offers the lowest latency, which is critical for minimizing packet loss and jitter, thus ensuring a smoother experience for the application. In scenarios where latency is paramount, it is often more beneficial to select a path that minimizes delay, even if it means accepting a lower bandwidth, provided that the bandwidth is still adequate for the application’s needs. In conclusion, when configuring SR-TE policies, it is crucial to analyze the trade-offs between latency and bandwidth. In this case, Path B is the most appropriate choice, as it aligns best with the application’s requirements for low latency, thereby enhancing overall performance and user experience.
Incorrect
Path A has a latency of 20 ms and a bandwidth of 100 Mbps. While it offers a decent bandwidth, its latency is higher than that of Path B. Path B, with a latency of 15 ms, is the lowest latency option available, but it has a bandwidth of only 50 Mbps. This could potentially lead to congestion if the application requires more than 50 Mbps, which may not be suitable for high-demand scenarios. Path C, on the other hand, has a latency of 25 ms and a bandwidth of 150 Mbps. Although it provides the highest bandwidth, the increased latency makes it less desirable for an application that prioritizes low latency. Given the application’s sensitivity to latency, Path B emerges as the optimal choice despite its lower bandwidth. It offers the lowest latency, which is critical for minimizing packet loss and jitter, thus ensuring a smoother experience for the application. In scenarios where latency is paramount, it is often more beneficial to select a path that minimizes delay, even if it means accepting a lower bandwidth, provided that the bandwidth is still adequate for the application’s needs. In conclusion, when configuring SR-TE policies, it is crucial to analyze the trade-offs between latency and bandwidth. In this case, Path B is the most appropriate choice, as it aligns best with the application’s requirements for low latency, thereby enhancing overall performance and user experience.
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Question 29 of 30
29. Question
In a corporate network, a network engineer is tasked with implementing Quality of Service (QoS) to ensure that voice traffic is prioritized over regular data traffic. The engineer decides to use Differentiated Services Code Point (DSCP) values to classify and mark packets. If the voice traffic is assigned a DSCP value of 46 (Expedited Forwarding), and the data traffic is assigned a DSCP value of 0 (Best Effort), what is the expected behavior of the network when both types of traffic are transmitted simultaneously during peak hours? Additionally, consider the impact of congestion on the overall performance of the voice service.
Correct
During peak hours, when network congestion occurs, the QoS mechanisms come into play. The network switches and routers will use the DSCP markings to determine how to handle the packets. Since voice packets are marked with a higher priority (DSCP 46), they will be queued ahead of data packets (DSCP 0) in the event of congestion. This prioritization helps to minimize latency and jitter for voice traffic, which is critical for maintaining call quality. If congestion occurs, the network may still experience some level of packet loss; however, the QoS policies will ensure that voice packets are less likely to be dropped compared to data packets. This means that even under heavy load, the voice service will maintain a higher quality, with lower latency and fewer interruptions, compared to the data service, which may experience delays or drops. In summary, the correct behavior expected in this scenario is that voice packets will be prioritized, leading to lower latency and better call quality, even during periods of congestion. This highlights the importance of implementing QoS strategies in environments where different types of traffic have varying requirements for performance.
Incorrect
During peak hours, when network congestion occurs, the QoS mechanisms come into play. The network switches and routers will use the DSCP markings to determine how to handle the packets. Since voice packets are marked with a higher priority (DSCP 46), they will be queued ahead of data packets (DSCP 0) in the event of congestion. This prioritization helps to minimize latency and jitter for voice traffic, which is critical for maintaining call quality. If congestion occurs, the network may still experience some level of packet loss; however, the QoS policies will ensure that voice packets are less likely to be dropped compared to data packets. This means that even under heavy load, the voice service will maintain a higher quality, with lower latency and fewer interruptions, compared to the data service, which may experience delays or drops. In summary, the correct behavior expected in this scenario is that voice packets will be prioritized, leading to lower latency and better call quality, even during periods of congestion. This highlights the importance of implementing QoS strategies in environments where different types of traffic have varying requirements for performance.
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Question 30 of 30
30. Question
In a corporate network, a DHCP server is located in a different subnet than the clients that require IP addresses. To facilitate the communication between the DHCP clients and the server, a DHCP relay agent is configured on the router connecting the two subnets. If the DHCP server is assigned the IP address 192.168.1.10 and the relay agent is configured with the IP address 10.0.0.1, what is the correct process that occurs when a DHCP client sends a request for an IP address, and how does the relay agent handle the DHCP packets?
Correct
Importantly, the relay agent includes the original client’s IP address in the relay agent information option (option 82) of the packet. This allows the DHCP server to know which client is requesting an IP address, even though the request originated from a different subnet. Upon receiving the DHCPDISCOVER message, the DHCP server processes the request and sends back a DHCPOFFER message, which is also unicast back to the relay agent. The relay agent then forwards this DHCPOFFER message back to the original client, completing the cycle of communication. This process is essential for maintaining the functionality of DHCP in environments with multiple subnets, ensuring that clients can successfully obtain IP addresses from a centralized DHCP server. The other options present misunderstandings of the DHCP relay process, such as direct unicast communication that bypasses the relay agent or incorrect handling of DHCP messages. Understanding the role of the relay agent and the encapsulation of messages is critical for effective network management and troubleshooting in advanced routing scenarios.
Incorrect
Importantly, the relay agent includes the original client’s IP address in the relay agent information option (option 82) of the packet. This allows the DHCP server to know which client is requesting an IP address, even though the request originated from a different subnet. Upon receiving the DHCPDISCOVER message, the DHCP server processes the request and sends back a DHCPOFFER message, which is also unicast back to the relay agent. The relay agent then forwards this DHCPOFFER message back to the original client, completing the cycle of communication. This process is essential for maintaining the functionality of DHCP in environments with multiple subnets, ensuring that clients can successfully obtain IP addresses from a centralized DHCP server. The other options present misunderstandings of the DHCP relay process, such as direct unicast communication that bypasses the relay agent or incorrect handling of DHCP messages. Understanding the role of the relay agent and the encapsulation of messages is critical for effective network management and troubleshooting in advanced routing scenarios.