CCNA Final: Routing Protocols (New)

1. What are two functions of a router? (Choose two.)

It connects multiple IP networks.

It controls the flow of data via the use of Layer 2 addresses.

It determines the best path to send packets.

It manages the VLAN database.

It increases the size of the broadcast domain.

A router has two main functions. Firstly, it connects multiple IP networks by receiving packets from one network and forwarding them to another network. This allows different networks to communicate with each other. Secondly, a router determines the best path to send packets by analyzing the destination IP address and using routing protocols to find the most efficient route. By doing so, it ensures that packets reach their intended destination in the most optimal way possible.

Explanation

A router has two main functions. Firstly, it connects multiple IP networks by receiving packets from one network and forwarding them to another network. This allows different networks to communicate with each other. Secondly, a router determines the best path to send packets by analyzing the destination IP address and using routing protocols to find the most efficient route. By doing so, it ensures that packets reach their intended destination in the most optimal way possible.

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2.

Refer to the exhibit. An administrator is adding a new subnet of 50 hosts to R3. Which subnet address should be used for the new subnet that provides enough addresses while wasting a minimum of addresses?

192.168.1.0/24

192.168.1.48 /28

192.168.1.32/27

192.168.1.64/26

The subnet 192.168.1.64/26 should be used for the new subnet. This subnet provides enough addresses for 50 hosts while wasting a minimum of addresses. The /26 subnet mask allows for 64 addresses, which is more than enough for the 50 hosts required. Additionally, using this subnet ensures that only the necessary number of addresses are allocated, minimizing wastage.

Explanation

The subnet 192.168.1.64/26 should be used for the new subnet. This subnet provides enough addresses for 50 hosts while wasting a minimum of addresses. The /26 subnet mask allows for 64 addresses, which is more than enough for the 50 hosts required. Additionally, using this subnet ensures that only the necessary number of addresses are allocated, minimizing wastage.

3.

Refer to the exhibit. All router interfaces are configured with an IP address and are operational. If no routing protocols or static routes are configured, what information will be included in the show ip route command output for router A?

All of the 192.168.x.0 networks will be in the routing table.

Routes to networks 192.168.1.0/24, 192.168.2.0/24, and 192.168.3.0/24 will be in the routing table.

The routing table will be empty because routes and dynamic routes have not been configured.

A default route is automatically installed in the routing table to allow connectivity between the networks.

The correct answer is that routes to networks 192.168.1.0/24, 192.168.2.0/24, and 192.168.3.0/24 will be in the routing table. This is because all router interfaces are configured with an IP address and are operational. Therefore, the router will have knowledge of the directly connected networks and include them in its routing table.

Explanation

The correct answer is that routes to networks 192.168.1.0/24, 192.168.2.0/24, and 192.168.3.0/24 will be in the routing table. This is because all router interfaces are configured with an IP address and are operational. Therefore, the router will have knowledge of the directly connected networks and include them in its routing table.

4. Which routing protocol uses a hierarchical design with areas to optimize large network performance and scalability?

RIP

EIGRP

OSPF

IS-IS

OSPF (Open Shortest Path First) uses a hierarchical design with areas to optimize network performance and scalability. This approach reduces routing table size and limits the scope of route recalculations to specific areas, improving efficiency in large networks. OSPF's ability to segment a network into areas allows for better management of large and complex topologies, unlike RIP or EIGRP, which do not inherently support such a hierarchical structure.

Explanation

OSPF (Open Shortest Path First) uses a hierarchical design with areas to optimize network performance and scalability. This approach reduces routing table size and limits the scope of route recalculations to specific areas, improving efficiency in large networks. OSPF's ability to segment a network into areas allows for better management of large and complex topologies, unlike RIP or EIGRP, which do not inherently support such a hierarchical structure.

5.

Refer to the exhibit. Two routers are unable to establish an adjacency. What is the possible cause for this?

The two routers are connected on a multiaccess network.

The hello and dead intervals are different on the two routers.

They have different OSPF router IDs.

They have different process IDs.

The possible cause for the two routers being unable to establish an adjacency is that the hello and dead intervals are different on the two routers. The hello and dead intervals determine how often OSPF routers send hello packets to discover and maintain neighbor relationships. If the hello and dead intervals are not the same on both routers, they will not be able to synchronize their communication and establish an adjacency.

Explanation

The possible cause for the two routers being unable to establish an adjacency is that the hello and dead intervals are different on the two routers. The hello and dead intervals determine how often OSPF routers send hello packets to discover and maintain neighbor relationships. If the hello and dead intervals are not the same on both routers, they will not be able to synchronize their communication and establish an adjacency.

6.

Refer to the exhibit. All routes are advertised and fully operational on all routers. Which statement is true about the path that the data will take from router A to router B?

If RIPv1 is used with default configurations, the data will be load-balanced on all paths.

If EIGRP is used with default configurations, the data will be equally distributed between two paths — A, D, B and A, C, B. This means that the data will be split between these two paths, with half of the data going through A, D, B and the other half going through A, C, B. This load balancing technique helps to optimize network performance by distributing the traffic across multiple paths, reducing congestion and improving overall efficiency.

Explanation

If EIGRP is used with default configurations, the data will be equally distributed between two paths — A, D, B and A, C, B. This means that the data will be split between these two paths, with half of the data going through A, D, B and the other half going through A, C, B. This load balancing technique helps to optimize network performance by distributing the traffic across multiple paths, reducing congestion and improving overall efficiency.

7. A network administrator needs to configure a single router to load-balance the traffic over unequal cost paths. Which routing protocol should the administrator use?

EIGRP

OSPF

RIPv1

RIPv2

EIGRP should be used by the network administrator to configure the router for load-balancing the traffic over unequal cost paths. EIGRP (Enhanced Interior Gateway Routing Protocol) is a Cisco proprietary routing protocol that supports unequal cost load balancing. It allows the administrator to configure different metrics for different paths, enabling the router to distribute traffic across those paths based on their costs. OSPF, RIPv1, and RIPv2 do not support unequal cost load balancing, making EIGRP the correct choice for this scenario.

Explanation

EIGRP should be used by the network administrator to configure the router for load-balancing the traffic over unequal cost paths. EIGRP (Enhanced Interior Gateway Routing Protocol) is a Cisco proprietary routing protocol that supports unequal cost load balancing. It allows the administrator to configure different metrics for different paths, enabling the router to distribute traffic across those paths based on their costs. OSPF, RIPv1, and RIPv2 do not support unequal cost load balancing, making EIGRP the correct choice for this scenario.

8.

Refer to the exhibit. What summary address can Router2 advertise to Router1 to reach the three networks on Routers 3, 4, and 5 without advertising any public address space or overlapping the networks on Router1?

172.16.0.0/8

172.16.0.0/10

172.16.0.0/13

172.16.0.0/20

172.16.0.0/24

Router2 can advertise the summary address 172.16.0.0/13 to Router1 in order to reach the three networks on Routers 3, 4, and 5 without advertising any public address space or overlapping the networks on Router1. This summary address encompasses the range of IP addresses from 172.16.0.0 to 172.23.255.255, which covers all the networks on Routers 3, 4, and 5 without including any public address space or overlapping with the networks on Router1.

Explanation

Router2 can advertise the summary address 172.16.0.0/13 to Router1 in order to reach the three networks on Routers 3, 4, and 5 without advertising any public address space or overlapping the networks on Router1. This summary address encompasses the range of IP addresses from 172.16.0.0 to 172.23.255.255, which covers all the networks on Routers 3, 4, and 5 without including any public address space or overlapping with the networks on Router1.

9.

Refer to the exhibit. What information can be determined from the highlighted output?

R1 is originating the route 172.30.200.32/28.

Automatic summarization is disabled.

The 172.30.200.16/28 network is one hop away from R1.

A classful routing protocol is being used.

The highlighted output indicates that automatic summarization is disabled. This means that the router is not automatically summarizing the routes it learns from its neighbors when advertising them to other routers. Instead, it is advertising the specific subnets without summarizing them into larger network ranges.

Explanation

The highlighted output indicates that automatic summarization is disabled. This means that the router is not automatically summarizing the routes it learns from its neighbors when advertising them to other routers. Instead, it is advertising the specific subnets without summarizing them into larger network ranges.

10. A network administrator uses the RIP routing protocol to implement routing within an autonomous system. What are two characteristics of this protocol? (Choose two.)

It uses the Bellman-Ford algorithm to determine the best path.

It displays an actual map of the network topology.

It offers rapid convergence in large networks.

It periodically sends complete routing tables to all connected devices.

It is beneficial in complex and hierarchically designed networks.

RIP (Routing Information Protocol) uses the Bellman-Ford algorithm to determine the best path for routing within an autonomous system. This algorithm calculates the distance vector and selects the shortest path based on the number of hops. Additionally, RIP periodically sends complete routing tables to all connected devices, ensuring that all devices have the most up-to-date information about the network topology. This helps in maintaining accurate routing information and allows for efficient routing decisions.

Explanation

RIP (Routing Information Protocol) uses the Bellman-Ford algorithm to determine the best path for routing within an autonomous system. This algorithm calculates the distance vector and selects the shortest path based on the number of hops. Additionally, RIP periodically sends complete routing tables to all connected devices, ensuring that all devices have the most up-to-date information about the network topology. This helps in maintaining accurate routing information and allows for efficient routing decisions.

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11.

Refer to the exhibit. A ping between host A and host B is successful, but pings from host A to operational hosts on the Internet fail. What is the reason for this problem?

The FastEthernet interface of R1 is disabled.

One of the default routes is configured incorrectly.

A routing protocol is not configured on both routers.

The default gateway has not been configured on host A.

The reason for the problem is that one of the default routes is configured incorrectly. This means that the router is not able to properly route traffic to the operational hosts on the Internet. The incorrect configuration of the default route is causing the pings from host A to fail.

Explanation

The reason for the problem is that one of the default routes is configured incorrectly. This means that the router is not able to properly route traffic to the operational hosts on the Internet. The incorrect configuration of the default route is causing the pings from host A to fail.

12.

Refer to the exhibit. A new PC was deployed in the Sales network. It was given the host address of 192.168.10.31 with a default gateway of 192.168.10.17. The PC is not communicating with the network properly. What is the cause?

The default gateway is incorrect.

The address is in the wrong subnet.

The host address and default gateway are swapped.

192.168.10.31 is the broadcast address for this subnet.

The given host address of 192.168.10.31 is actually the broadcast address for this subnet. In a network, the broadcast address is used to send data to all devices on the network. Therefore, when the PC is configured with this address as its host address, it will not be able to communicate properly with other devices on the network.

Explanation

The given host address of 192.168.10.31 is actually the broadcast address for this subnet. In a network, the broadcast address is used to send data to all devices on the network. Therefore, when the PC is configured with this address as its host address, it will not be able to communicate properly with other devices on the network.

13.

The network shown in the diagram is having problems routing traffic. It is suspected that the problem is with the addressing scheme. What is the problem with the addressing used in the topology?

The address assigned to the Ethernet0 interface of Router1 is a broadcast address for that subnetwork.

The subnetwork configured on the serial link between Router1 and Router2 overlaps with the subnetwork assigned to Ethernet0 of Router3.

The subnetwork assigned to Ethernet0 of Router2 overlaps with the subnetwork assigned to Ethernet0 of Router3.

The problem with the addressing used in the topology is that the subnetwork configured on the serial link between Router1 and Router2 overlaps with the subnetwork assigned to Ethernet0 of Router3. This can cause routing issues as the routers may not be able to properly distinguish between the two subnetworks and route traffic accordingly.

Explanation

The problem with the addressing used in the topology is that the subnetwork configured on the serial link between Router1 and Router2 overlaps with the subnetwork assigned to Ethernet0 of Router3. This can cause routing issues as the routers may not be able to properly distinguish between the two subnetworks and route traffic accordingly.

14.

Refer to the exhibit. All routers are running RIPv1. The two networks 10.1.1.0/29 and 10.1.1.16/29 are unable to access each other. What can be the cause of this problem?

Because RIPv1 is a classless protocol, it does not support this access.

RIPv1 does not support discontiguous networks.

RIPv1 does not support load balancing.

RIPv1 does not support automatic summarization.

RIPv1 does not support discontiguous networks. This means that if the two networks 10.1.1.0/29 and 10.1.1.16/29 are not directly connected, RIPv1 will not be able to route traffic between them. In order for these networks to access each other, a different routing protocol that supports discontiguous networks would need to be used.

Explanation

RIPv1 does not support discontiguous networks. This means that if the two networks 10.1.1.0/29 and 10.1.1.16/29 are not directly connected, RIPv1 will not be able to route traffic between them. In order for these networks to access each other, a different routing protocol that supports discontiguous networks would need to be used.

15. A network is configured with the IP, IPX, and AppleTalk protocols. Which routing protocol is recommended for this network?

RIPv1

RIPv2

EIGRP

OSPF

EIGRP (Enhanced Interior Gateway Routing Protocol) is recommended for this network because it supports multiple protocols, including IP, IPX, and AppleTalk. EIGRP is a Cisco proprietary routing protocol that provides fast convergence, load balancing, and scalability. It is designed to work well in large and complex networks, making it a suitable choice for a network configured with multiple protocols.

Explanation

EIGRP (Enhanced Interior Gateway Routing Protocol) is recommended for this network because it supports multiple protocols, including IP, IPX, and AppleTalk. EIGRP is a Cisco proprietary routing protocol that provides fast convergence, load balancing, and scalability. It is designed to work well in large and complex networks, making it a suitable choice for a network configured with multiple protocols.

16.

Refer to the exhibit. The routers in the exhibit are running the EIGRP routing protocol. What statement is true regarding how packets will travel from the 172.16.1.0/16 network to the 192.168.200.0/24 network?

The router chooses the first path that it learned and installs only that route in the routing table.

The router chooses the path with the lowest administrative distance and installs only that route in the routing table.

The correct answer is that the router installs all the equal cost paths in the routing table and performs equal cost load balancing to send packets out multiple exit interfaces. This means that the router will have multiple routes to the destination network and will distribute the traffic across these paths to achieve load balancing. This helps in optimizing network performance and ensuring efficient utilization of available resources.

Explanation

The correct answer is that the router installs all the equal cost paths in the routing table and performs equal cost load balancing to send packets out multiple exit interfaces. This means that the router will have multiple routes to the destination network and will distribute the traffic across these paths to achieve load balancing. This helps in optimizing network performance and ensuring efficient utilization of available resources.

17. A router has EIGRP configured as the only routing protocol. In what way might EIGRP respond if there is no feasible successor route to a destination network and the successor route fails?

It broadcasts hello packets to all routers in the network to re-establish neighbor adjacencies.

It sends queries to adjacent neighbors until a new successor route is found.

It immediately sends its entire routing table to its neighbors.

It will set the metric for the failed route to infinity.

When there is no feasible successor route to a destination network and the successor route fails, EIGRP will send queries to adjacent neighbors until a new successor route is found. This is done to determine if any of the adjacent neighbors have a feasible successor route that can be used as an alternate path to the destination network. By sending queries, EIGRP can find a new successor route and re-establish connectivity to the destination network.

Explanation

When there is no feasible successor route to a destination network and the successor route fails, EIGRP will send queries to adjacent neighbors until a new successor route is found. This is done to determine if any of the adjacent neighbors have a feasible successor route that can be used as an alternate path to the destination network. By sending queries, EIGRP can find a new successor route and re-establish connectivity to the destination network.

18. Which two statements are true regarding link-state routing protocols? (Choose two.)

They are aware of the complete network topology.

They offer rapid convergence times in large networks.

They do not include subnet masks in their routing updates.

They rely on decreasing hop counts to determine the best path.

They pass their entire routing tables to their directly connected neighbors only.

Link-state routing protocols, such as OSPF and IS-IS, maintain a complete and up-to-date map of the entire network topology. This allows them to have a comprehensive understanding of the network, including all routers and links. This information is used to calculate the shortest path to each destination. Additionally, link-state protocols provide rapid convergence times in large networks as they can quickly adapt to changes in the network by flooding link-state updates and recalculating the shortest path. Therefore, the statements "They are aware of the complete network topology" and "They offer rapid convergence times in large networks" are both true.

Explanation

Link-state routing protocols, such as OSPF and IS-IS, maintain a complete and up-to-date map of the entire network topology. This allows them to have a comprehensive understanding of the network, including all routers and links. This information is used to calculate the shortest path to each destination. Additionally, link-state protocols provide rapid convergence times in large networks as they can quickly adapt to changes in the network by flooding link-state updates and recalculating the shortest path. Therefore, the statements "They are aware of the complete network topology" and "They offer rapid convergence times in large networks" are both true.

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19.

Refer to the exhibit. The routers are properly configured using a dynamic routing protocol with default settings, and the network is fully converged. Router A is forwarding data to router E. Which statement is true about the routing path?

If the network uses the RIP protocol, router A will determine that all paths have equal cost.

If the network uses the RIP protocol, router A will update only the A-C-E path in its routing table.

If the network uses the EIGRP routing protocol, router A will determine that path A-D-E has the lowest cost.

The correct answer is "If the network uses the RIP protocol, router A will determine that all paths have equal cost." This is because RIP (Routing Information Protocol) is a distance-vector routing protocol that uses hop count as the metric to determine the best path. In RIP, all paths are considered to have equal cost if they have the same number of hops. Therefore, router A will determine that all paths to router E have equal cost and will choose one of them to forward the data.

Explanation

The correct answer is "If the network uses the RIP protocol, router A will determine that all paths have equal cost." This is because RIP (Routing Information Protocol) is a distance-vector routing protocol that uses hop count as the metric to determine the best path. In RIP, all paths are considered to have equal cost if they have the same number of hops. Therefore, router A will determine that all paths to router E have equal cost and will choose one of them to forward the data.

20.

Refer to the exhibit. R1 knows two routes, Path A and Path B, to the Ethernet network attached to R3. R1 learned Path A to network 10.2.0.0/16 from a static route and Path B to network 10.2.0.0/16 from EIGRP. Which route will R1 install in its routing table?

Both routes are installed and load balancing occurs across both paths.

The route via Path B is installed because the EIGRP route has the best metric to network 10.2.0.0/16.

The route via Path A is installed because the static route has the best metric to network 10.2.0.0/16.

The route via Path B is installed because the EIGRP route has the lowest administrative distance to network 10.2.0.0/16.

The route via Path A is installed because the static route has the lowest administrative distance to network 10.2.0.0/16.

The correct answer is that the route via Path A is installed because the static route has the lowest administrative distance to network 10.2.0.0/16. Administrative distance is a measure of the trustworthiness of the source of the routing information, where lower values indicate higher trust. In this case, the static route has a lower administrative distance compared to the EIGRP route, so it is considered more trustworthy and is installed in the routing table.

Explanation

The correct answer is that the route via Path A is installed because the static route has the lowest administrative distance to network 10.2.0.0/16. Administrative distance is a measure of the trustworthiness of the source of the routing information, where lower values indicate higher trust. In this case, the static route has a lower administrative distance compared to the EIGRP route, so it is considered more trustworthy and is installed in the routing table.

21. Which two components are used to determine the router ID in the configuration of the OSPF routing process? (Choose two.)

The IP address of the first FastEthernet interface

The highest IP address of any logical interface

The highest IP address of any physical interface

The default gateway IP address

The priority value of 1 on any physical interface

The router ID in the configuration of the OSPF routing process is determined by two components: the highest IP address of any logical interface and the highest IP address of any physical interface. These two components are used to uniquely identify the router in the OSPF network. The router ID is important for the OSPF routing process as it is used to identify the router's OSPF advertisements and to establish OSPF neighbor relationships.

Explanation

The router ID in the configuration of the OSPF routing process is determined by two components: the highest IP address of any logical interface and the highest IP address of any physical interface. These two components are used to uniquely identify the router in the OSPF network. The router ID is important for the OSPF routing process as it is used to identify the router's OSPF advertisements and to establish OSPF neighbor relationships.

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22.

Refer to the exhibit. The network administrator issues the command no ip classless on Router1. What forwarding action will take place on a packet that is received by Router1 and is destined for host 192.168.0.26?

The packet will be dropped.

The packet will be forwarded to the gateway of last resort.

The packet will match the 192.168.0.0 network and be forwarded out Serial 0/0.

The packet will most closely match the 192.168.0.8 subnet and be forwarded out Serial 0/1.

When the command "no ip classless" is issued on Router1, it means that Router1 will not perform classless routing and will only route packets to directly connected networks. In this case, the packet with the destination IP address of 192.168.0.26 does not fall within any directly connected network of Router1. Therefore, Router1 will not have a route to forward the packet and as a result, the packet will be dropped.

Explanation

When the command "no ip classless" is issued on Router1, it means that Router1 will not perform classless routing and will only route packets to directly connected networks. In this case, the packet with the destination IP address of 192.168.0.26 does not fall within any directly connected network of Router1. Therefore, Router1 will not have a route to forward the packet and as a result, the packet will be dropped.

23. Which routing protocol utilizes path vector mechanisms to maintain loop-free routing between autonomous systems?

OSPF

RIP

EIGRP

BGP

BGP (Border Gateway Protocol) uses a path vector mechanism to maintain loop-free routing between autonomous systems (AS). It tracks the full path of routes (AS numbers) to prevent routing loops in interdomain routing. BGP ensures each AS knows the exact path a route has taken, which makes it suitable for managing routing on the Internet. This contrasts with protocols like OSPF and RIP, which operate within a single autonomous system or domain.

Explanation

BGP (Border Gateway Protocol) uses a path vector mechanism to maintain loop-free routing between autonomous systems (AS). It tracks the full path of routes (AS numbers) to prevent routing loops in interdomain routing. BGP ensures each AS knows the exact path a route has taken, which makes it suitable for managing routing on the Internet. This contrasts with protocols like OSPF and RIP, which operate within a single autonomous system or domain.

24.

Refer to the exhibit. To implement the RIPv2 protocol, the network administrator runs the commands as displayed. However, the show ip protocol command fails to display any output. How can the administrator solve the problem that is indicated by the lack of output from this command?

Include the default-information originate command.

Include the no auto-summary command.

Specify the network for which RIP routing has to be enabled.

Implement RIPv2 authentication in the network.

The correct answer is to specify the network for which RIP routing has to be enabled. By specifying the network, the administrator can ensure that RIP routing is enabled for that specific network. This will allow the show ip protocol command to display the appropriate output.

Explanation

The correct answer is to specify the network for which RIP routing has to be enabled. By specifying the network, the administrator can ensure that RIP routing is enabled for that specific network. This will allow the show ip protocol command to display the appropriate output.

25. Which routing protocol uses a combination of distance-vector and link-state properties, and is classified as a hybrid routing protocol?

OSPF

EIGRP

RIP

BGP

EIGRP (Enhanced Interior Gateway Routing Protocol) is a hybrid routing protocol developed by Cisco. It combines the best features of distance-vector and link-state protocols, offering fast convergence, scalability, and efficient routing updates. Unlike purely distance-vector protocols like RIP or purely link-state protocols like OSPF, EIGRP uses a mix of both techniques to achieve efficient and reliable routing. BGP, while powerful, is mainly used as a path-vector protocol for inter-domain routing.

Explanation

EIGRP (Enhanced Interior Gateway Routing Protocol) is a hybrid routing protocol developed by Cisco. It combines the best features of distance-vector and link-state protocols, offering fast convergence, scalability, and efficient routing updates. Unlike purely distance-vector protocols like RIP or purely link-state protocols like OSPF, EIGRP uses a mix of both techniques to achieve efficient and reliable routing. BGP, while powerful, is mainly used as a path-vector protocol for inter-domain routing.

26.

Refer to the exhibit. Router R2 is configured properly and all interfaces are functional. Router R1 has been installed recently. Host A is unable to ping host B.

Which procedure can resolve this problem?

Configure a static route on R1 using the IP address of the serial interface on R1.

Configure a default route on R1 with the exit interface Fa0/0 on R1.

Configure a static route on R1 using the IP address of S0/0/0 on R2.

Configure a default route on R1 using the IP address of Fa0/0 on R2.

The correct answer is to configure a static route on R1 using the IP address of S0/0/0 on R2. This is because the issue is with the communication between R1 and R2, and specifically with the serial interface S0/0/0 on R2. By configuring a static route on R1 using the IP address of S0/0/0 on R2, R1 will be able to properly route traffic to R2 and resolve the problem.

Explanation

The correct answer is to configure a static route on R1 using the IP address of S0/0/0 on R2. This is because the issue is with the communication between R1 and R2, and specifically with the serial interface S0/0/0 on R2. By configuring a static route on R1 using the IP address of S0/0/0 on R2, R1 will be able to properly route traffic to R2 and resolve the problem.

27.

Refer to the exhibit. The network is running the RIP routing protocol. Network 10.0.0.0 goes down. Which statement is true regarding how the routers in this topology will respond to this event?

Router5 flushes the unreachable route from its routing table in 30 seconds.

Router4 will learn about the failed route 30 seconds later in the next periodic update.

Router5 will send Router4 a triggered update with a metric of 16 for network 10.0.0.0.

Split horizon will prevent Router4 from fowarding packets to the 10.0.0.0 network until the holddown timer expires.

When network 10.0.0.0 goes down, Router5 will send a triggered update to Router4. This triggered update will inform Router4 about the failed route and will include a metric of 16 for network 10.0.0.0. This metric indicates that the route is unreachable. Therefore, the correct statement is that Router5 will send Router4 a triggered update with a metric of 16 for network 10.0.0.0.

Explanation

When network 10.0.0.0 goes down, Router5 will send a triggered update to Router4. This triggered update will inform Router4 about the failed route and will include a metric of 16 for network 10.0.0.0. This metric indicates that the route is unreachable. Therefore, the correct statement is that Router5 will send Router4 a triggered update with a metric of 16 for network 10.0.0.0.

28. What should be considered when troubleshooting a problem with the establishment of neighbor relationships between OSPF routers? (Choose two.)

OSPF interval timers mismatch

Administrative distance mismatch

Interface network type mismatch

No loopback interface configured

Gateway of last resort not redistributed

When troubleshooting a problem with the establishment of neighbor relationships between OSPF routers, two factors that should be considered are OSPF interval timers mismatch and interface network type mismatch. If the interval timers between routers are not synchronized, it can cause issues with neighbor relationships. Additionally, if the network types configured on the interfaces of the routers do not match, it can also prevent the establishment of neighbor relationships.

Explanation

When troubleshooting a problem with the establishment of neighbor relationships between OSPF routers, two factors that should be considered are OSPF interval timers mismatch and interface network type mismatch. If the interval timers between routers are not synchronized, it can cause issues with neighbor relationships. Additionally, if the network types configured on the interfaces of the routers do not match, it can also prevent the establishment of neighbor relationships.

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29.

The Suffolk router is directly connected to the networks shown in the graphic and has a default route that points to the Richmond router. All interfaces are active and properly addressed. However, when the workstation on network 172.29.5.0/24 sends a packet to destination address 172.29.198.5, it is discarded by the Suffolk router. What can be a reason for this result?

IP classless has been disabled on the Suffolk router.

The ip subnet-zero command was not configured on the Suffolk router.

The Richmond router is in a different autonomous system than the Suffolk router.

The route was ignored if the Richmond router did not include the 172.29.198.0/24 network in its routing updates.

The reason for the packet being discarded by the Suffolk router could be that IP classless has been disabled on the router. This means that the router does not have the capability to forward packets to a network that is not directly connected to it or is not in its routing table. Since the destination address 172.29.198.5 is not directly connected to the Suffolk router and is also not in its routing table, the router discards the packet.

Explanation

The reason for the packet being discarded by the Suffolk router could be that IP classless has been disabled on the router. This means that the router does not have the capability to forward packets to a network that is not directly connected to it or is not in its routing table. Since the destination address 172.29.198.5 is not directly connected to the Suffolk router and is also not in its routing table, the router discards the packet.

30.

Refer to the exhibit. A network administrator has configured R1 as shown, and all interfaces are functioning correctly. A ping from R1 to 172.16.1.1 fails. What could be the cause of this problem?

The serial interface on R1 is configured incorrectly.

The default route is configured incorrectly.

The default-information originate command must be issued on R1.

Autosummarization must be disabled on R1.

The default route is configured incorrectly. This means that R1 does not have a route to forward the ping packet to the destination IP address 172.16.1.1. Since the default route is used when there is no specific route in the routing table for the destination, the ping fails because R1 does not know where to send the packet.

Explanation

The default route is configured incorrectly. This means that R1 does not have a route to forward the ping packet to the destination IP address 172.16.1.1. Since the default route is used when there is no specific route in the routing table for the destination, the ping fails because R1 does not know where to send the packet.

31.

Refer to the exhibit. The show cdp neighbors command was run at R1. Which two facts about the newly detected device can be determined from the output? (Choose two.)

ABCD is a router that is connected to R1.

ABCD is a non-CISCO device that is connected to R1

The device is connected at the Serial0/0/1 interface of R1.

R1 is connected at the S0/0/1 interface of device ABCD.

ABCD does not support switching capability.

From the output of the "show cdp neighbors" command, it can be determined that ABCD is a router that is connected to R1. This is because the command displays information about the neighboring devices, and in this case, it shows that ABCD is a device connected to R1. Additionally, the output also indicates that the device is connected at the Serial0/0/1 interface of R1.

Explanation

From the output of the "show cdp neighbors" command, it can be determined that ABCD is a router that is connected to R1. This is because the command displays information about the neighboring devices, and in this case, it shows that ABCD is a device connected to R1. Additionally, the output also indicates that the device is connected at the Serial0/0/1 interface of R1.

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32. A network administrator has been asked to configure a network using a classful IP addressing scheme. Which statement is true about the IP addressing that will be used?

Classful IP addresses can be used only when static routing is configured in the network.

Classful IP addresses allow the network/host boundary to occur at any bit in the 32-bit address.

not-available-via-ai

Explanation

not-available-via-ai

33.

Refer to the exhibit. Both routers are using the RIP protocol. Devices on the 192.168.1.1 network can ping the S0/0/0 interface on R2 but cannot ping devices on the 192.168.2.1 network.

What is a possible cause of this problem?

The routers are configured with different versions of RIP.

R2 is not forwarding the routing updates.

The R1 configuration should include the no auto-summary command.

The maximum path number has been exceeded.

The possible cause of the problem is that the routers are configured with different versions of RIP. This can cause compatibility issues and prevent devices on the 192.168.1.1 network from being able to ping devices on the 192.168.2.1 network.

Explanation

The possible cause of the problem is that the routers are configured with different versions of RIP. This can cause compatibility issues and prevent devices on the 192.168.1.1 network from being able to ping devices on the 192.168.2.1 network.

34.

Refer to the exhibit. All interfaces are configured with the correct IP addresses and subnet masks. OSPF has been configured as the routing protocol. During troubleshooting, it is determined that hosts on network B can ping the Lo0 interface on R1 but are unable to reach hosts on network A. What is the cause of the problem?

Routers R1 and R2 have incorrect router IDs configured.

Router R1 is unable to form a neighbor relationship with router R2.

Routers R1 and R2 have been configured in different OSPF areas.

The configuration of router R1 fails to include network A in the OSPF routing process.

The problem is caused by the configuration of router R1, which fails to include network A in the OSPF routing process. This means that router R1 is not advertising network A to other routers in the OSPF network, resulting in hosts on network B being unable to reach hosts on network A.

Explanation

The problem is caused by the configuration of router R1, which fails to include network A in the OSPF routing process. This means that router R1 is not advertising network A to other routers in the OSPF network, resulting in hosts on network B being unable to reach hosts on network A.

35. What are two reasons for the occurrence of a routing loop? (Choose two.)

Slow convergence

Incorrectly configured static routes

Routes that are learned via two routing protocols

Static and dynamic routing being used on the same router

Lack of a default route on the router that connects to the Internet

Routing loops can occur due to slow convergence, which is the time it takes for routers to update their routing tables after a change in the network topology. During this time, routers may still forward packets based on outdated information, leading to loops. Additionally, incorrectly configured static routes can also cause routing loops. If static routes are misconfigured, they may point to the wrong next hop or create circular paths, resulting in packets being continuously forwarded in a loop.

Explanation

Routing loops can occur due to slow convergence, which is the time it takes for routers to update their routing tables after a change in the network topology. During this time, routers may still forward packets based on outdated information, leading to loops. Additionally, incorrectly configured static routes can also cause routing loops. If static routes are misconfigured, they may point to the wrong next hop or create circular paths, resulting in packets being continuously forwarded in a loop.

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36. When a router boots, what is the default order to locate the Cisco IOS if there is no boot system command?

ROM, TFTP server, flash

Flash, TFTP server, ROM

Flash, NVRAM, TFTP server

NVRAM, TFTP server, flash

When a router boots, it first looks for the Cisco IOS in the flash memory. If it doesn't find the IOS there, it then tries to locate it on a TFTP server. If the IOS is not found on the TFTP server, the router will finally look for it in ROM. Therefore, the default order to locate the Cisco IOS if there is no boot system command is flash, TFTP server, ROM.

Explanation

When a router boots, it first looks for the Cisco IOS in the flash memory. If it doesn't find the IOS there, it then tries to locate it on a TFTP server. If the IOS is not found on the TFTP server, the router will finally look for it in ROM. Therefore, the default order to locate the Cisco IOS if there is no boot system command is flash, TFTP server, ROM.

37.

Refer to the exhibit. Which statement is true concerning the routing configuration?

Using dynamic routing instead of static routing would have required fewer configuration steps.

The 10.1.1.0/24 and 10.1.2.0/24 routes have adjacent boundaries and should be summarized.

Packets routed to the R2 Fast Ethernet interface require two routing table lookups.

The static route will not work correctly.

The given correct answer states that packets routed to the R2 Fast Ethernet interface require two routing table lookups. This means that when a packet is received by R2 and needs to be forwarded out of the Fast Ethernet interface, R2 will have to consult its routing table twice in order to determine the appropriate next hop for the packet. This suggests that there are multiple possible next hop options for the packet, and R2 needs to perform two lookups to determine the best one.

Explanation

The given correct answer states that packets routed to the R2 Fast Ethernet interface require two routing table lookups. This means that when a packet is received by R2 and needs to be forwarded out of the Fast Ethernet interface, R2 will have to consult its routing table twice in order to determine the appropriate next hop for the packet. This suggests that there are multiple possible next hop options for the packet, and R2 needs to perform two lookups to determine the best one.

38. What is the first step OSPF and IS-IS routers take in building a shortest path first database?

Learn about directly connected networks

Send hello to discover neighbors and form adjacencies

Choose successors and feasible successors to populate the topology table

Flood LSPs to all neighbors informing them of all known networks and their link states

The first step OSPF and IS-IS routers take in building a shortest path first database is to learn about directly connected networks. This means that the routers gather information about the networks that are directly connected to them, such as their IP addresses and subnet masks. This information is then used to create a database of all the networks that can be reached directly from each router. This database is essential for the routers to determine the shortest path to a destination network.

Explanation

The first step OSPF and IS-IS routers take in building a shortest path first database is to learn about directly connected networks. This means that the routers gather information about the networks that are directly connected to them, such as their IP addresses and subnet masks. This information is then used to create a database of all the networks that can be reached directly from each router. This database is essential for the routers to determine the shortest path to a destination network.

39. What are three features of CDP? (Choose three.)

Tests Layer 2 connectivity

Operates a OSI layers 2 and 3

Enabled by default on each interface

Used for debugging Layer 4 connectivity issues

Provides information on directly connected devices that have CDP enabled

CDP (Cisco Discovery Protocol) is a proprietary Cisco protocol that operates at OSI layers 1 and 2. It is enabled by default on each interface and provides information on directly connected devices that have CDP enabled. CDP can be used to test Layer 2 connectivity between devices. However, it is not used for debugging Layer 4 connectivity issues.

Explanation

CDP (Cisco Discovery Protocol) is a proprietary Cisco protocol that operates at OSI layers 1 and 2. It is enabled by default on each interface and provides information on directly connected devices that have CDP enabled. CDP can be used to test Layer 2 connectivity between devices. However, it is not used for debugging Layer 4 connectivity issues.

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40. What is the function of the OSPF LSR packet?

It is used to confirm the receipt of LSUs.

It is used to establish and maintain adjacency with other OSPF routers.

It is used by the receiving routers to request more information about any entry in the DBD.

It is used to check the database synchronization between routers.

The OSPF LSR (Link State Request) packet is used by the receiving routers to request more information about any entry in the DBD (Database Description). This packet allows the receiving router to ask for specific information about the state of the network from the sending router. By requesting more information, the receiving router can ensure that its own database is synchronized with the sending router's database, helping to maintain accurate and up-to-date routing information within the OSPF network.

Explanation

The OSPF LSR (Link State Request) packet is used by the receiving routers to request more information about any entry in the DBD (Database Description). This packet allows the receiving router to ask for specific information about the state of the network from the sending router. By requesting more information, the receiving router can ensure that its own database is synchronized with the sending router's database, helping to maintain accurate and up-to-date routing information within the OSPF network.

41.

Refer to the exhibit. What will happen if interface Serial0/0/1 goes down on Router1?

The Dijkstra algorithm will calculate the feasible successor.

DUAL will query neighbors for a route to network 192.168.1.0.

Neighbor 172.16.3.2 will be promoted to the feasible successor.

Traffic destined to the 192.168.1.0 network will be dropped immediately due to lack of a feasible successor.

If interface Serial0/0/1 goes down on Router1, DUAL (Diffusing Update Algorithm) will query neighbors for a route to network 192.168.1.0. This means that the router will send query messages to its neighboring routers to find an alternative path to reach the network 192.168.1.0. The purpose of this is to find a feasible successor, which is a backup route that can be used in case the primary route becomes unavailable. Therefore, the correct answer is that DUAL will query neighbors for a route to network 192.168.1.0.

Explanation

If interface Serial0/0/1 goes down on Router1, DUAL (Diffusing Update Algorithm) will query neighbors for a route to network 192.168.1.0. This means that the router will send query messages to its neighboring routers to find an alternative path to reach the network 192.168.1.0. The purpose of this is to find a feasible successor, which is a backup route that can be used in case the primary route becomes unavailable. Therefore, the correct answer is that DUAL will query neighbors for a route to network 192.168.1.0.

42. What are two tasks that must be completed before two routers can use OSPF to form a neighbor adjacency? (Choose two.)

The routers must elect a designated router.

The routers must agree on the network type.

The routers must use the same dead interval.

The routers must exchange link state requests.

The routers must exchange database description packets.

Before two routers can use OSPF to form a neighbor adjacency, they must agree on the network type and use the same dead interval. The network type determines how OSPF operates on a particular network segment, and both routers must agree on this to ensure proper communication. The dead interval is a timer that determines when a router is considered unreachable, and both routers must use the same dead interval for accurate neighbor detection and adjacency formation.

Explanation

Before two routers can use OSPF to form a neighbor adjacency, they must agree on the network type and use the same dead interval. The network type determines how OSPF operates on a particular network segment, and both routers must agree on this to ensure proper communication. The dead interval is a timer that determines when a router is considered unreachable, and both routers must use the same dead interval for accurate neighbor detection and adjacency formation.

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43. Which two statements are true about the startup configuration in a router? (Choose two.)

The router uses the startup configuration file to start POST.

If the Cisco IOS cannot be found, the router enters setup mode.

The bootstrap program searches for the startup configuration file in NVRAM.

If the startup config file cannot be found, the router enters ROMMON mode.

The router searches for a TFTP server if the startup configuration file is absent at the default location.

The first statement is true because the bootstrap program, which is a part of the router's firmware, searches for the startup configuration file in NVRAM (non-volatile random-access memory) during the boot process. This file contains the configuration settings for the router.

The fourth statement is also true because if the startup configuration file cannot be found in NVRAM, the router enters ROMMON (ROM Monitor) mode. In this mode, the router can be used to troubleshoot and recover from various issues.

Therefore, the correct answer is that the bootstrap program searches for the startup configuration file in NVRAM, and the router searches for a TFTP (Trivial File Transfer Protocol) server if the startup configuration file is absent at the default location.

Explanation

The first statement is true because the bootstrap program, which is a part of the router's firmware, searches for the startup configuration file in NVRAM (non-volatile random-access memory) during the boot process. This file contains the configuration settings for the router.

The fourth statement is also true because if the startup configuration file cannot be found in NVRAM, the router enters ROMMON (ROM Monitor) mode. In this mode, the router can be used to troubleshoot and recover from various issues.

Therefore, the correct answer is that the bootstrap program searches for the startup configuration file in NVRAM, and the router searches for a TFTP (Trivial File Transfer Protocol) server if the startup configuration file is absent at the default location.

Submit

44.

Refer to the exhibit. A network administrator successfully pings R1 from R3. Next, the administrator runs the show cdp neighbors command on R3. The output of this command is displayed.

What are two reasons for the absence of R1 in the output? (Choose two.)

There is a Layer 2 connectivity problem between R1 and R3.

The Fa0/0 interface of R1 is configured with an incorrect IP address.

The no cdp run command has been run at R1.

The no cdp enable command has been run at Fa0/1 interface of R3.

R1 is powered off.

The absence of R1 in the output of the show cdp neighbors command on R3 can be explained by two reasons. First, the "no cdp run" command has been run at R1, which disables the CDP protocol on R1 and prevents it from sending CDP advertisements. Second, the "no cdp enable" command has been run at the Fa0/1 interface of R3, which disables CDP on that interface and prevents R3 from receiving CDP advertisements from R1. These two actions result in R1 not being visible in the output of the show cdp neighbors command on R3.

Explanation

The absence of R1 in the output of the show cdp neighbors command on R3 can be explained by two reasons. First, the "no cdp run" command has been run at R1, which disables the CDP protocol on R1 and prevents it from sending CDP advertisements. Second, the "no cdp enable" command has been run at the Fa0/1 interface of R3, which disables CDP on that interface and prevents R3 from receiving CDP advertisements from R1. These two actions result in R1 not being visible in the output of the show cdp neighbors command on R3.

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45. A network is using RIP as the routing protocol. The router learns that the same destination can be reached via five different paths. All paths have the same metric, and all routers are using the default operation.
Which statement correctly describes the path used by the router?

It will use the first available path to the destination.

It will use only the first two paths that it learned.

It will use four of the five paths.

It will load-balance using all five paths.

In a network using RIP as the routing protocol, the router will use four of the five available paths to reach the destination. This is because RIP uses a maximum of four equal-cost paths to load-balance traffic. Since all paths have the same metric and the default operation is being used, the router will distribute the traffic among the four paths, providing load balancing and redundancy.

Explanation

In a network using RIP as the routing protocol, the router will use four of the five available paths to reach the destination. This is because RIP uses a maximum of four equal-cost paths to load-balance traffic. Since all paths have the same metric and the default operation is being used, the router will distribute the traffic among the four paths, providing load balancing and redundancy.

46.

Refer to the exhibit. What action will R2 take for a packet that is destined for 192.168.2.0?

It will drop the packet.

It will forward the packet via the S0/0/0 interface.

It will forward the packet via the Fa0/0 interface.

It will forward the packet to R1.

R2 does not have a route to 192.168.2.0 in its routing table. However, it has a default route (0.0.0.0/0) pointing to R1. Therefore, R2 will forward the packet to R1, which is its next hop for any unknown destination.

Explanation

R2 does not have a route to 192.168.2.0 in its routing table. However, it has a default route (0.0.0.0/0) pointing to R1. Therefore, R2 will forward the packet to R1, which is its next hop for any unknown destination.

47.

Refer to the exhibit. The network administrator is testing network connectivity by issuing the tracert command from host A to host B. Given the exhibited output on host A, what are two possible routing table issues on the network? (Choose two.)

Router1 is missing a route to the 172.16.0.0 network

Router2 is missing a route to the 10.0.0.0 network

Router2 is missing a route to the 172.16.0.0 network

Router3 is missing a route to the 10.0.0.0 network

Router3 is missing a route to the 192.168.0.0 network

The exhibited output shows that the tracert command from host A to host B is unable to reach the 172.16.0.0 network and the 10.0.0.0 network. This suggests that there might be routing table issues on the network. The first possible routing table issue is that Router2 is missing a route to the 172.16.0.0 network, as indicated by the inability to reach that network. The second possible routing table issue is that Router3 is missing a route to the 10.0.0.0 network, again indicated by the inability to reach that network.

Explanation

The exhibited output shows that the tracert command from host A to host B is unable to reach the 172.16.0.0 network and the 10.0.0.0 network. This suggests that there might be routing table issues on the network. The first possible routing table issue is that Router2 is missing a route to the 172.16.0.0 network, as indicated by the inability to reach that network. The second possible routing table issue is that Router3 is missing a route to the 10.0.0.0 network, again indicated by the inability to reach that network.

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48.

Refer to the exhibit. All routers are running the same routing protocol. Based on the exhibit and its displayed commands, which statement is true?

The wildcard mask is incorrectly configured.

A default route must be configured on every router.

Routers B, C, and D have no access to the Internet.

The link to the ISP is not advertised by the routing protocol process.

The exhibit shows the output of the "show ip route" command on Router A. The routing table does not have a route to the ISP's network, indicated by the absence of the ISP's network address in the routing table. This suggests that the link to the ISP is not being advertised by the routing protocol process running on the routers. Therefore, the correct statement is that the link to the ISP is not advertised by the routing protocol process.

Explanation

The exhibit shows the output of the "show ip route" command on Router A. The routing table does not have a route to the ISP's network, indicated by the absence of the ISP's network address in the routing table. This suggests that the link to the ISP is not being advertised by the routing protocol process running on the routers. Therefore, the correct statement is that the link to the ISP is not advertised by the routing protocol process.

49.

Refer to the exhibit. R2 is configured correctly. The network administrator has configured R1 as shown. Which two facts are true about the forwarding of route information by R1? (Choose two.)

R1 will forward the route information for subnet 192.168.100.0/30.

R1 will not forward route information for subnet 192.168.100.4/30.

R1 will forward the route information with an administrative distance set to 50.

R1 will forward the summarized route information for network 192.168.100.0/24.

R1 will forward route information for subnet 10.10.10.0/30 out the serial interface.

R1 will forward the route information for subnet 192.168.100.0/30 because it is directly connected to R1. R1 will not forward route information for subnet 192.168.100.4/30 because it is not directly connected to R1.

Explanation

R1 will forward the route information for subnet 192.168.100.0/30 because it is directly connected to R1. R1 will not forward route information for subnet 192.168.100.4/30 because it is not directly connected to R1.

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50.

Refer to the exhibit. Although both the routers can ping the serial interface of their neighbors, they are unable to ping the Ethernet interfaces of other routers. Which two statements are true for this network? (Choose two.)

The administrative distance has been set to 50 on both routers.

R2 is learning about network 192.168.1.0.

R1 is learning about network 192.168.2.0.

The network 10.1.1.0 command has not been run on both routers.

Autosummarization is enabled on both routers.

The network 10.1.1.0 command has not been run on both routers. This means that the routers do not have the correct routing information for the network 10.1.1.0, which is causing them to be unable to ping the Ethernet interfaces of the other routers. Autosummarization is enabled on both routers, which means that they are summarizing the routing information for their connected networks, which could also be causing issues with routing to the specific Ethernet interfaces.

Explanation

The network 10.1.1.0 command has not been run on both routers. This means that the routers do not have the correct routing information for the network 10.1.1.0, which is causing them to be unable to ping the Ethernet interfaces of the other routers. Autosummarization is enabled on both routers, which means that they are summarizing the routing information for their connected networks, which could also be causing issues with routing to the specific Ethernet interfaces.

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