An Interesting Quiz On CCNA 2 Chapter 10
In chapter ten we got to understand how data is moved across the network, from opening an application to receiving data. What else can you remember from CCNA 2 chapter 10? Take up this interesting quiz and know for sure. Remember to keep an eye out for chapter 11 quiz.
- 1.
When are link-state packets sent to neighbors?
- A.
Every 30 seconds
- B.
Every 180 seconds
- C.
After the holddown time expires
- D.
When a link goes up or down
- E.
When a routing loop occurs
Correct Answer
D. When a link goes up or downExplanation
Link-state packets are sent to neighbors when a link goes up or down. This is because link-state protocols, such as OSPF, use a proactive approach to update routing tables by exchanging information about network topology changes. When a link goes up or down, the router sends link-state packets to its neighboring routers to inform them about the change in the network. This allows the routers to update their routing tables accordingly and maintain an accurate view of the network topology.Rate this question:
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- 2.
Refer to the exhibit. Which statement correctly describes the path traffic would take from the 10.0.0.0/24 network to the 192.168.1.0/24 network if a link-state routing protocol was in use?
- A.
BOS -> ATL because this path is the least hops
- B.
BOS -> ATL because this path is highest cost
- C.
BOS -> ORL -> JAX -> ATL because this path is the lowest cost
- D.
Traffic would load balance across all links
Correct Answer
C. BOS -> ORL -> JAX -> ATL because this path is the lowest costExplanation
The given answer correctly describes the path that traffic would take from the 10.0.0.0/24 network to the 192.168.1.0/24 network if a link-state routing protocol was in use. According to the answer, the traffic would go from BOS (Boston) to ORL (Orlando), then to JAX (Jacksonville), and finally to ATL (Atlanta). This path is considered the lowest cost, meaning it has the least amount of network resources or hops required to reach the destination network.Rate this question:
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- 3.
Why is it difficult for routing loops to occur in networks that use link-state routing?
- A.
Each router builds a simple view of the network based on hop count.
- B.
Routers flood the network with LSAs to discover routing loops.
- C.
Each router builds a complete and synchronized view of the network.
- D.
Routers use hold-down timers to prevent routing loops.
Correct Answer
C. Each router builds a complete and synchronized view of the network.Explanation
In networks that use link-state routing, each router builds a complete and synchronized view of the network. This means that every router has accurate and up-to-date information about the entire network topology, including the state of all other routers and links. With this comprehensive knowledge, routers can make informed routing decisions and avoid routing loops. By having a complete view of the network, routers can determine the shortest and most efficient paths to destination networks, minimizing the chances of loops occurring.Rate this question:
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- 4.
What two statements correctly describe the link state routing process? (Choose two.)
- A.
All routers in the area have link state databases
- B.
Each router in the area floods LSPs to all neighbors
- C.
LSPs use the reserved multicast address of 224.0.0.10 to reach neighbors
- D.
Routing loops are prevented by running the Diffusing Update Algorithm (DUAL)
- E.
Reliable Transport Protocol (RTP) is the protocol used by for the delivery and reception of LSPs
Correct Answer(s)
A. All routers in the area have link state databases
B. Each router in the area floods LSPs to all neighborsExplanation
The link state routing process involves all routers in the area having link state databases, which contain information about the network topology. Each router in the area floods Link State Packets (LSPs) to all of its neighbors, informing them about its own state and the state of the network. This flooding ensures that all routers have a consistent view of the network. The use of the reserved multicast address of 224.0.0.10 allows the LSPs to reach all neighbors efficiently. The Diffusing Update Algorithm (DUAL) is used to prevent routing loops. Reliable Transport Protocol (RTP) is not the protocol used for the delivery and reception of LSPs.Rate this question:
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- 5.
What action does a link-state router take immediately upon receipt of an LSP from a neighboring router?
- A.
Floods the LSP to neighbors
- B.
Calculates the SPF algorithm
- C.
Runs the Bellman-Ford algorithm
- D.
Computes the best path to the destination network
Correct Answer
A. Floods the LSP to neighborsExplanation
Upon receiving an LSP (Link State Packet) from a neighboring router, a link-state router immediately floods the LSP to its other neighboring routers. This process ensures that all routers within the network have the most up-to-date information about the network's topology. By flooding the LSP, the router ensures that all routers in the network are aware of the changes or updates in the network's state.Rate this question:
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- 6.
What two events will cause a link state router to send LSPs to all neighbors? (Choose two
- A.
30 second timer expires
- B.
Whenever the network topology changes
- C.
Immediately after the Bellman-Ford algorithm has run
- D.
Immediately after the DUAL FSM has built the topology database
- E.
Upon initial startup of router or routing protocol
Correct Answer(s)
B. Whenever the network topology changes
E. Upon initial startup of router or routing protocolExplanation
A link state router will send LSPs to all neighbors whenever the network topology changes because this ensures that all routers have the most up-to-date information about the network. Additionally, LSPs are also sent upon the initial startup of the router or routing protocol to establish the initial network topology and allow routers to build their databases. This ensures that all routers have a consistent view of the network and can make accurate routing decisions.Rate this question:
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- 7.
Refer to the exhibit. What does JAX do with link-state packets from ORL?
- A.
Sends out its updated routing table to both ORL and BOS routers
- B.
Sends out the individual link-state packets out the interface connected to BOS
- C.
Queries BOS to see if it has a better route
- D.
Only adds it to the local routing table and performs no other actions
Correct Answer
B. Sends out the individual link-state packets out the interface connected to BOSExplanation
JAX sends out the individual link-state packets out the interface connected to BOS. This means that JAX forwards the link-state packets it receives from ORL to the BOS router through the interface that is connected to BOS. It does not send its updated routing table to both ORL and BOS routers, query BOS for a better route, or only add the packets to the local routing table without taking any other actions.Rate this question:
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- 8.
Which database or table must be identical on all link-state routers within an area in order to construct an accurate SPF tree?
- A.
Routing table
- B.
Adjacency table
- C.
Link-state database
- D.
Neighbor table
- E.
Topology database
Correct Answer
C. Link-state databaseExplanation
The link-state database must be identical on all link-state routers within an area in order to construct an accurate SPF tree. The link-state database contains information about the network topology, including the state of links and routers. By having an identical link-state database, the routers can have a consistent view of the network and make accurate decisions on the shortest path to a destination.Rate this question:
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- 9.
What feature do modern link-state protocols provide to minimize processing and memory requirements?
- A.
Splitting routing topologies into smaller areas
- B.
Assigning lower process priorities to route calculations
- C.
Using update timers to restrict routing updates
- D.
Strict split horizon rules to reduce routing table entries
Correct Answer
A. Splitting routing topologies into smaller areasExplanation
Modern link-state protocols provide the feature of splitting routing topologies into smaller areas in order to minimize processing and memory requirements. By dividing the network into smaller areas, each area can have its own routing table, reducing the overall size and complexity of the routing tables. This allows for more efficient routing calculations and reduces the amount of memory required to store the routing information. Additionally, it helps to limit the scope of routing updates, as changes in one area do not need to be propagated to the entire network, further reducing processing and memory requirements.Rate this question:
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- 10.
What is the final step in the link state routing process?
- A.
Successors are placed into the routing table
- B.
SPF computes best path to each destination network
- C.
LSPs are flooded to all neighbors to converge the network
- D.
DUAL algorithm is run to find best path to destination networks
Correct Answer
B. SPF computes best path to each destination networkExplanation
The final step in the link state routing process is when SPF (Shortest Path First) computes the best path to each destination network. SPF algorithm calculates the shortest path based on the link state database and assigns a cost to each possible route. This process helps determine the most efficient route for forwarding packets to their intended destinations. Once SPF has computed the best path for each network, the successors are then placed into the routing table for future reference.Rate this question:
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- 11.
What are two advantages of using a link-state routing protocol instead of a distance vector routing protocol? (Choose two.)
- A.
The topology database eliminates the need for a routing table.
- B.
Each router independently determines the route to each network.
- C.
Link-state protocols require less router processor power than distance vector protocols
- D.
After the inital LSP flooding, they generally require less bandwidth to communicate changes in a topology.
- E.
Frequent periodic updates are sent to minimize the number of incorrect routes in the topological database.
Correct Answer(s)
B. Each router independently determines the route to each network.
D. After the inital LSP flooding, they generally require less bandwidth to communicate changes in a topology.Explanation
Link-state routing protocols offer two advantages over distance vector routing protocols. Firstly, each router independently determines the route to each network. This means that each router has a complete understanding of the network topology and can make informed decisions on the best path to each destination. Secondly, after the initial LSP (Link State Packet) flooding, link-state protocols generally require less bandwidth to communicate changes in the network topology. This is because only the changes or updates are sent, rather than sending the entire routing table as in distance vector protocols.Rate this question:
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- 12.
Which algorithm is run by link-state routing protocols to calculate the shortest path to destination networks?
- A.
DUAL
- B.
Dijkstra
- C.
Bellman-Ford
- D.
Diffie-Hellman
Correct Answer
B. DijkstraExplanation
Link-state routing protocols, such as OSPF and IS-IS, use the Dijkstra algorithm to calculate the shortest path to destination networks. The Dijkstra algorithm is a graph search algorithm that calculates the shortest path from a source node to all other nodes in a weighted graph. It determines the shortest path by iteratively selecting the node with the smallest distance and updating the distances of its neighboring nodes. This process continues until the shortest path to all nodes is determined. Therefore, the correct answer is Dijkstra.Rate this question:
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- 13.
which routers will router D receive hello packets?
- A.
A and E
- B.
B and C
- C.
A, B, C, and E
- D.
C only
Correct Answer
B. B and CExplanation
Router D will receive hello packets from routers B and C. This is because routers B and C are directly connected to router D, so they will send hello packets to router D to establish and maintain neighbor relationships. Router A is not directly connected to router D, so it will not send hello packets to router D. Similarly, router E is also not directly connected to router D, so it will not send hello packets to router D. Therefore, the correct answer is B and C.Rate this question:
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- 14.
What speeds up convergence in a network using link-state routing?
- A.
Updates triggered by network changes
- B.
Updates sent at regular intervals
- C.
Updates sent only to directly connected neighbors
- D.
Updates that include complete routing tables
Correct Answer
A. Updates triggered by network changesExplanation
Updates triggered by network changes speed up convergence in a network using link-state routing because they allow routers to quickly update their routing tables when there is a change in the network topology. This means that routers only need to exchange information about the specific changes that have occurred, rather than sending complete routing tables at regular intervals. By only sending updates when necessary, the network can converge more quickly and efficiently.Rate this question:
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- 15.
A new network administrator is given the task of selecting an appropriate dynamic routing protocol for a software development company. The company has over 100 routers, uses CIDR and VLSM, requires fast convergence, and uses both Cisco and non-Cisco equipment. Which routing protocol is appropriate for this company?
- A.
RIP version 2
- B.
IGRP
- C.
EIGRP
- D.
OSPF
- E.
BGP
Correct Answer
D. OSPFExplanation
OSPF (Open Shortest Path First) is the appropriate routing protocol for this company. OSPF is suitable for large networks with multiple routers, such as the software development company mentioned in the question. It supports CIDR and VLSM, which are essential for efficient IP address allocation. OSPF also provides fast convergence, allowing for quick routing updates and minimal downtime. Additionally, OSPF is vendor-neutral, meaning it can be used with both Cisco and non-Cisco equipment, making it a versatile choice for the company's network.Rate this question:
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- 16.
Refer to the exhibit. What kind of information would be seen in an LSP sent from router JAX to router ATL?
- A.
Hop count
- B.
Uptime of the route
- C.
Cost of the link
- D.
A list of all the routing protocols in use
Correct Answer
C. Cost of the linkExplanation
In an LSP (Link State Packet) sent from router JAX to router ATL, the information that would be seen is the cost of the link. LSPs are used in link-state routing protocols to exchange information about the network topology. The cost of the link refers to the metric used to determine the desirability of a particular link. It helps routers in calculating the shortest path to a destination. Therefore, the LSP sent from JAX to ATL would include the cost of the link between them.Rate this question:
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- 17.
Which two routing protocols use Dijkstra’s shortest path first algorithm? (Choose two.)
- A.
RIPv1
- B.
RIPv2
- C.
IS-IS
- D.
BGP
- E.
OSPF
Correct Answer(s)
C. IS-IS
E. OSPFExplanation
IS-IS and OSPF are the two routing protocols that use Dijkstra's shortest path first algorithm. This algorithm is used to determine the shortest path between two nodes in a network by calculating the cost of each possible path. Both IS-IS (Intermediate System to Intermediate System) and OSPF (Open Shortest Path First) are interior gateway protocols that use this algorithm to determine the best path for routing packets through a network.Rate this question:
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- 18.
What is the default administrative distance for OSPF?
- A.
90
- B.
100
- C.
110
- D.
115
- E.
120
Correct Answer
C. 110Explanation
The default administrative distance for OSPF is 110. Administrative distance is a measure of the trustworthiness of a routing protocol. It is used by routers to determine which route to choose when multiple routing protocols provide routes to the same destination. A lower administrative distance indicates a more preferred route. In the case of OSPF, the default administrative distance is 110, which means that OSPF routes are generally preferred over routes from other routing protocols with higher administrative distances.Rate this question:
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- 19.
Refer to the exhibit. Router A is correctly configured for OSPF. Which OSPF configuration statement or set of statements was entered for router B to generate the exhibited routing table?
- A.
B(config-router)# network 192.168.1.0 0.0.0.3 area 0
- B.
B(config-router)# network 10.16.1.0 0.0.0.224 area 0
- C.
B(config-router)# network 10.16.1.0 255.255.255.224 area 0
- D.
B(config-router)# network 192.168.1.0 255.255.255.255 area 0 B(config-router)# network 10.0.0.0 255.255.255.255 area 0
Correct Answer
A. B(config-router)# network 192.168.1.0 0.0.0.3 area 0Explanation
The correct answer is B(config-router)# network 192.168.1.0 0.0.0.3 area 0. This statement configures router B to include the network 192.168.1.0 with a wildcard mask of 0.0.0.3 in OSPF for area 0. This means that any IP address within the range of 192.168.1.0 to 192.168.1.3 will be included in OSPF routing updates.Rate this question:
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- 20.
Refer to the exhibit. What configuration statements would give the results that are shown in the output of the show ip protocols command?
- A.
B(config)# int fa0/0 B(config-if)# router-id 192.168.1.5
- B.
B(config)# int lo0 B(config-if)# ip address 192.168.1.5
- C.
B(config)# router ospf 1 B(config-router)# router-id 192.168.1.5
- D.
B (config)# router ospf 1 B(config-router)# ip address 192.168.1.5
Correct Answer
C. B(config)# router ospf 1 B(config-router)# router-id 192.168.1.5Explanation
The correct answer is the configuration statements "B(config)# router ospf 1" and "B(config-router)# router-id 192.168.1.5". These statements configure OSPF (Open Shortest Path First) routing protocol with process ID 1 on the router. The "router-id" command sets the router ID to 192.168.1.5, which is the same as the IP address configured on interface lo0. This configuration will result in the output of the "show ip protocols" command displaying the OSPF process ID and the router ID as 192.168.1.5.Rate this question:
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- 21.
Refer to the exhibit. How many OSPF adjacencies must be formed to build the complete topology if a DR or BDR were not elected in this OSPF network?
- A.
4
- B.
5
- C.
6
- D.
7
- E.
10
Correct Answer
C. 6Explanation
In an OSPF network, each router forms an adjacency with every other router in the network. In this scenario, if a DR (Designated Router) or BDR (Backup Designated Router) is not elected, each router will still form an adjacency with the other five routers in the network. Therefore, to build the complete topology, six OSPF adjacencies must be formed.Rate this question:
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- 22.
Refer to the exhibit. The network administrator wants to set the router ID of Router1 to 192.168.100.1. What steps can the administrator take to accomplish this?
- A.
Shut down the loop back interface
- B.
Use the OSPF router-id 192.168.100.1 command
- C.
Use the clear ip ospf process command
- D.
Nothing, the router-id of Router1 is already 192.168.100.1
Correct Answer
D. Nothing, the router-id of Router1 is already 192.168.100.1Explanation
The correct answer is "nothing, the router-id of Router1 is already 192.168.100.1". This means that the network administrator does not need to take any additional steps to set the router ID of Router1 to 192.168.100.1 because it is already set to that value.Rate this question:
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- 23.
Refer to the exhibit. Router1 and Router2 are running OSPF. The show ip ospf neighbor command reveals no neighbors. What is a possible cause?
- A.
OSPF autonomous system IDs do not match.
- B.
OSPF process IDs do not match.
- C.
OSPF network types are identical.
- D.
OSPF hello or dead timers do not match.
Correct Answer
D. OSPF hello or dead timers do not match.Explanation
A possible cause for the lack of OSPF neighbors could be that the OSPF hello or dead timers do not match between Router1 and Router2. The OSPF hello and dead timers determine how often OSPF routers send hello packets to discover and maintain neighbor relationships. If the timers do not match, the routers may not be able to establish a neighbor relationship and therefore, the show ip ospf neighbor command would not display any neighbors.Rate this question:
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- 24.
Refer to the exhibit. All routers are running OSPF. What cost would JAX put in its routing table for the 10.0.0.0/24 network?
- A.
2
- B.
156
- C.
1564
- D.
1785
- E.
1787
Correct Answer
E. 1787Explanation
The cost that JAX would put in its routing table for the 10.0.0.0/24 network is 1787.Rate this question:
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- 25.
Refer to the exhibit. What does the "2" stand for in the router ospf 2 statement?
- A.
The number 2 is the autonomous system number.
- B.
The number 2 indicates the number of networks advertised by OSPF.
- C.
The number 2 identifies this particular instance of OSPF on this router.
- D.
The number 2 indicates the priority of the OSPF process on this router.
Correct Answer
C. The number 2 identifies this particular instance of OSPF on this router.Explanation
The number 2 in the "router ospf 2" statement identifies this particular instance of OSPF on this router. It is used to differentiate between multiple instances of OSPF running on the same router. Each OSPF instance is assigned a unique number to distinguish it from others.Rate this question:
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- 26.
Refer to the exhibit. Which network command or set of commands will cause OSPF to be enabled to send and receive packets for any R1 interface connected to the exhibited subnets?
- A.
R1(config-router)# network 10.0.0.0 0.0.0.0 area 0
- B.
R1(config-router)# network 10.1.0.0 0.0.0.255 area 0 R1(config-router)# network 10.1.1.0 0.0.0.255 area 0 R1(config-router)# network 10.1.2.4 0.0.0.3 area 0
- C.
R1(config-router)# network 10.1.0.0 0.0.0.255 area 0 R1(config-router)# network 10.2.0.0 0.0.0.255 area 0
- D.
R1(config-router)# network 10.0.0.0 0.0.255.255 area 0
Correct Answer
B. R1(config-router)# network 10.1.0.0 0.0.0.255 area 0 R1(config-router)# network 10.1.1.0 0.0.0.255 area 0 R1(config-router)# network 10.1.2.4 0.0.0.3 area 0Explanation
The correct answer is a combination of three network commands:
1. "network 10.1.0.0 0.0.0.255 area 0" enables OSPF for any interface with an IP address in the range of 10.1.0.0 to 10.1.0.255.
2. "network 10.1.1.0 0.0.0.255 area 0" enables OSPF for any interface with an IP address in the range of 10.1.1.0 to 10.1.1.255.
3. "network 10.1.2.4 0.0.0.3 area 0" enables OSPF for the specific IP address 10.1.2.4 with a wildcard mask of 0.0.0.3.
By using these three commands, OSPF will be enabled to send and receive packets for any R1 interface connected to the exhibited subnets.Rate this question:
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- 27.
What range of networks will be advertised in the OSPF updates by the command Router1(config-router)# network 192.168.0.0 0.0.15.255 area 100?
- A.
192.168.0.0/24 through 192.168.0.15/24
- B.
192.168.0.0/24 through 192.168.15.0/24
- C.
192.168.15.0/24 through 192.168.31.0/24
- D.
192.168.15.0/24 through 192.168.255.0/24
- E.
192.168.16.0/24 through 192.168.255.0/24
Correct Answer
B. 192.168.0.0/24 through 192.168.15.0/24Explanation
The command "network 192.168.0.0 0.0.15.255 area 100" will advertise networks in the range of 192.168.0.0/24 through 192.168.15.0/24 in the OSPF updates. This is because the wildcard mask 0.0.15.255 allows for a range of 16 subnets, with each subnet having a /24 prefix length. Therefore, the networks in the range of 192.168.0.0/24 through 192.168.15.0/24 will be advertised.Rate this question:
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- 28.
What does OSPF use to calculate the cost to a destination network?
- A.
Bandwidth
- B.
Bandwidth and hop count
- C.
Bandwidth and reliability
- D.
Bandwidth, load, and reliablity
Correct Answer
A. BandwidthExplanation
OSPF uses bandwidth to calculate the cost to a destination network. The cost is determined by the bandwidth of the links along the path to the destination. OSPF assigns a cost value to each link based on its bandwidth, with higher bandwidth links having lower costs. This allows OSPF to choose the most efficient path to a destination network based on the available bandwidth.Rate this question:
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- 29.
Refer to the exhibit. What does the "O*E2" from the "O*E2 0.0.0.0/0 [110/1] via 192.168.1.1, 00:05:34, Serial0/0" line represent?
- A.
An internal type 2 OSPF route.
- B.
An internal type 2 OSPF route.
- C.
An external OSPF route from two different sources.
- D.
An external OSPF route that will not increment in cost.
- E.
The route was distributed into OSPF from a type 2 router.
Correct Answer
D. An external OSPF route that will not increment in cost.Explanation
The "O*E2" in the given output represents an external OSPF route that will not increment in cost. This means that the route is being advertised into OSPF from an external source and will not have its cost increased as it is propagated through the OSPF network. This can be useful in scenarios where the external route has a higher cost compared to the internal routes, allowing for better path selection within the OSPF network.Rate this question:
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- 30.
A fully converged five router OSPF network has been running successfully for several weeks. All configurations have been saved and no static routes are used. If one router looses power and reboots, what information will be in its routing table after the configuration file is loaded but before OSPF has converged?
- A.
All routes for the entire network will be present.
- B.
Directly connected networks that are operational will be in the routing table.
- C.
Because the SPF algorithm has not completed all calculations, no routes will be in the table.
- D.
A summary route for all previously learned routes will automatically appear in the routing table until all LSPs have been received by the router.
Correct Answer
B. Directly connected networks that are operational will be in the routing table.Explanation
After the router loses power and reboots, the configuration file is loaded but OSPF has not yet converged. This means that the SPF algorithm has not completed all calculations. Therefore, the routing table will only contain directly connected networks that are operational. Other routes for the entire network or a summary route for previously learned routes will not be present until OSPF has fully converged.Rate this question:
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- 31.
Refer to the exhibit. What must be received between neighbors to prevent the dead time that is shown in the exhibit from reaching zero?
- A.
Any traffic through the router interfaces
- B.
Routing database updates
- C.
Hello packets
- D.
BPDU packets
Correct Answer
C. Hello packetsExplanation
To prevent the dead time from reaching zero, hello packets must be received between neighbors. Hello packets are used in network protocols to establish and maintain neighbor relationships. They are sent periodically to confirm that the neighboring devices are still active and reachable. By receiving hello packets, the router can ensure that there is ongoing communication and connectivity with its neighbors, preventing the dead time from expiring.Rate this question:
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- 32.
Refer to the exhibit. All routers have been configured with the interface priorities that are shown. All routers were restarted simultaneously. The results of the DR/BDR election are shown. What can be concluded about this network?
- A.
Router C cannot win a DR election under any circumstances.
- B.
If the link for interface 192.168.1.4 goes down, router B will become the new DR.
- C.
The highest router ID was most likely determined via an OSPF router-id statement or statements.
- D.
If a new router is added with a higher router ID than router D, it will become the DR.
Correct Answer
C. The highest router ID was most likely determined via an OSPF router-id statement or statements.Explanation
The fact that the highest router ID was most likely determined via an OSPF router-id statement or statements can be concluded from the given information. This is because the router with the highest router ID (Router D) has been elected as the DR. The router ID is a unique identifier assigned to each router in OSPF, and it is used to determine the DR and BDR in the network. Since Router D has the highest router ID, it has been elected as the DR. This suggests that the router ID was most likely manually configured using an OSPF router-id statement or statements.Rate this question:
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- 33.
Refer to the exhibit. What is the cost of the route to the 10.0.0.0 network
- A.
2
- B.
110
- C.
1786
- D.
1.544
Correct Answer
C. 1786Explanation
The cost of the route to the 10.0.0.0 network is 1786.Rate this question:
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- 34.
What three parameters must be indentical between OSPF routers in order to form an adjacency? (Choose three.)
- A.
Area id
- B.
K-values
- C.
Metric value
- D.
Hello interval
- E.
Network type
Correct Answer(s)
A. Area id
D. Hello interval
E. Network typeExplanation
In order for OSPF routers to form an adjacency, three parameters must be identical between them: area id, hello interval, and network type. The area id specifies the OSPF area to which the routers belong, ensuring that they are in the same area. The hello interval determines how often the routers send hello packets to discover and maintain neighbor relationships. The network type defines the type of network link, such as point-to-point or broadcast, and must be the same for adjacency formation. The other options, K-values and metric value, are not relevant parameters for forming an adjacency.Rate this question:
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- 35.
Which two statements describe the use of OSPF DR/BDR elections? (Choose two.)
- A.
Elections are always optional
- B.
Elections are required in all WAN networks
- C.
Elections are required in point-to-point networks
- D.
Elections are required in broadcast multiaccess networks
- E.
Elections are sometimes required in NBMA networks
Correct Answer(s)
D. Elections are required in broadcast multiaccess networks
E. Elections are sometimes required in NBMA networksExplanation
OSPF (Open Shortest Path First) uses DR (Designated Router) and BDR (Backup Designated Router) elections in certain network types. The first statement is incorrect because elections are not optional, they are required in specific network types. The second statement is incorrect because elections are not required in all WAN networks. The third statement is incorrect because elections are not required in point-to-point networks. The fourth statement is correct as elections are required in broadcast multiaccess networks. The fifth statement is also correct as elections are sometimes required in NBMA (Non-Broadcast Multiaccess) networks.Rate this question:
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- 36.
Refer to the exhibit. Routers A, B, C, and D are all running OSPF with default router IDs and OSPF interface priorities. Loopback interfaces are not configured and all interfaces are operational. Router D is the DR and router C is the BDR. What happens immediately after the following commands are entered on router A? A(config)# interface fa0/0 A(config-if)# ip ospf priority 255
- A.
A will become the DR. D will become the BDR.
- B.
A will become the DR. C will remain the BDR.
- C.
D will remain the DR. A will become the BDR
- D.
D will remain the DR. C will remain the BDR.
Correct Answer
D. D will remain the DR. C will remain the BDR.Explanation
When the command "ip ospf priority 255" is entered on router A, it sets the OSPF priority of the interface fa0/0 to the highest value possible, which is 255. However, this command alone does not affect the election of the DR (Designated Router) and BDR (Backup Designated Router). The election of the DR and BDR is based on the OSPF interface priorities and router IDs, not the interface priorities alone. Since the question states that all routers have default router IDs and OSPF interface priorities, the existing DR and BDR (D and C respectively) will remain unchanged. Therefore, D will remain the DR and C will remain the BDR.Rate this question:
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- 37.
Refer to the exhibit. When OSPF is operational in the exhibited network, what neighbor relationship is developed between Router1 and Router2?
- A.
A FULL adjacency is formed.
- B.
A 2WAY adjacency is formed
- C.
Router2 will become the DR and Router1 will become the BDR.
- D.
Both routers will become DROTHERS.
Correct Answer
A. A FULL adjacency is formed.Explanation
When OSPF is operational in the exhibited network, a FULL adjacency is formed between Router1 and Router2. This means that both routers have exchanged their entire link-state databases and are fully synchronized. They can now exchange routing updates and share information about the network.Rate this question:
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- 38.
Refer to the exhibit. Assuming that the routers have default interface OSPF priorities and no configured loopback interfaces, what two roles will router B play on each network segment? (Choose two.)
- A.
DR for network 192.168.1.200
- B.
BDR for network 192.168.1.200
- C.
DROTHER on 192.168.1.200
- D.
DR for network 192.168.1.204
- E.
BDR for network 192.168.1.204
Correct Answer(s)
A. DR for network 192.168.1.200
E. BDR for network 192.168.1.204Explanation
Router B will play the role of the designated router (DR) for the network 192.168.1.200. This means that it will be responsible for maintaining the OSPF adjacency and exchanging routing information with other routers on that network segment. Additionally, Router B will also play the role of the backup designated router (BDR) for the network 192.168.1.204. This means that it will act as a backup to the DR on that network segment and will take over the role of the DR if the current DR fails.Rate this question:
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