“OSPF Practice Test”
(226).jpg "OSPF Practice Test - Quiz")
By IMS Asia (https://www. Imsasia. Com)
Questions and Answers
- 1.
Which RFC describes OSPF version 2?
- A.
2328
- B.
2823
- C.
2238
- D.
2283
Correct Answer
A. 2328Explanation
RFC 2328 describes OSPF version 2.Rate this question:
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- 2.
Which protocols can OSPF do routing for?
- A.
DECNET
- B.
Vines
- C.
IPX
- D.
IP
Correct Answer
D. IPExplanation
OSPF (Open Shortest Path First) is a routing protocol that is specifically designed for IP networks. It is used to determine the best path for routing IP packets within a network. Therefore, OSPF can only do routing for IP protocols and not for DECNET, Vines, or IPX protocols.Rate this question:
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- 3.
Which 2 characteristics describe OSPF ?
- A.
Classfull
- B.
Classless
- C.
Link State Protocol
- D.
Distance Vector Protocol
Correct Answer(s)
B. Classless
C. Link State ProtocolExplanation
OSPF is a link state protocol that is used in routing to exchange information about network topology. It is designed to work with variable length subnet masks (VLSM) which allows for more efficient use of IP addresses. This characteristic makes OSPF a classless routing protocol. Therefore, the two characteristics that describe OSPF are classless and link state protocol.Rate this question:
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- 4.
OSPF Dijkstra calculations are done in serial
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
The statement "OSPF Dijkstra calculations are done in serial" is false. OSPF (Open Shortest Path First) is a link-state routing protocol that uses the Dijkstra algorithm to calculate the shortest path between routers. However, these calculations are not done in serial, meaning they are not done one after another. Instead, OSPF routers exchange link-state advertisements and build a database of network topology, and then each router independently runs the Dijkstra algorithm on its own database to determine the shortest paths. Therefore, the calculations are done in parallel or independently.Rate this question:
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- 5.
Which types of addresses are used as destinations for OSPF ?
- A.
Multicast
- B.
Broadcast
- C.
Unicast
- D.
Anycast
Correct Answer(s)
A. Multicast
C. UnicastExplanation
Multicast: OSPF uses multicast addresses (224.0.0.5 for all OSPF routers, and 224.0.0.6 for all designated routers) to send OSPF packets to all routers in the network segment.
Unicast: OSPF also uses unicast addresses to send OSPF packets directly to specific routers.
Broadcast and Anycast addresses are not used as destinations for OSPF.Rate this question:
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- 6.
Pick the multicast addresses that OSPF uses:
- A.
224.0.1.5
- B.
224.0.0.1
- C.
224.0.0.5
- D.
224.0.0.2
Correct Answer
C. 224.0.0.5Explanation
OSPF (Open Shortest Path First) is a routing protocol that uses multicast addresses to communicate and exchange routing information between OSPF routers. The correct answer, 224.0.0.5, is one of the multicast addresses used by OSPF. This address is specifically used for OSPF All SPF routers, which means it is used to send OSPF routing updates to all OSPF routers in the network. The other multicast addresses mentioned (224.0.1.5, 224.0.0.1, and 224.0.0.2) are not specifically used by OSPF for routing updates.Rate this question:
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- 7.
Which formula is used by default by Cisco devices to do cost calculations?
- A.
108/bandwidth
- B.
107/bandwidth
- C.
1008/bandwidth
- D.
It does not do a calculation, cost needs to be manually assigned
Correct Answer
A. 108/bandwidthExplanation
Cisco devices use the formula 108/bandwidth by default to calculate costs. This formula is commonly used in routing protocols like OSPF to determine the cost of a link based on its bandwidth. The higher the bandwidth, the lower the cost, indicating a more favorable path for routing. This formula ensures that higher bandwidth links are preferred over lower bandwidth links in the routing process.Rate this question:
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- 8.
OSPF supports different authentication methods, what does option 1 represent?
- A.
No Authentication
- B.
Clear Text Authentication
- C.
MD5 Authentication
- D.
Not a valid option
Correct Answer
B. Clear Text AuthenticationExplanation
Option 1, Clear Text Authentication, represents one of the authentication methods supported by OSPF. Clear Text Authentication means that OSPF exchanges authentication information in plain text, without any encryption or hashing. This method is considered to be the least secure as the authentication information can be easily intercepted and read by unauthorized individuals. It is recommended to use more secure authentication methods like MD5 Authentication to ensure the confidentiality and integrity of OSPF communication.Rate this question:
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- 9.
By default OSPF will load balance over how many equal cost paths? (Maximum supported)
- A.
2
- B.
3
- C.
4
- D.
OSPF will not load balance by default
Correct Answer
C. 4Explanation
OSPF will load balance over a maximum of four equal cost paths by default. This means that if there are multiple paths with the same cost to reach a destination, OSPF will distribute the traffic evenly across these paths, maximizing the utilization of available resources and improving network performance.Rate this question:
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- 10.
OSPF is represented as protocol number _____ in the IP packet.
- A.
98
- B.
88
- C.
89
- D.
None of the above
Correct Answer
C. 89Explanation
The correct answer is 89. OSPF is represented as protocol number 89 in the IP packet.Rate this question:
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- 11.
Pick the fields that HAVE to match between OSPF neighbors for them to be able establish adjacencies.
- A.
A. Router ID
- B.
B. Stub Flag
- C.
C. Link cost
- D.
D. Timers
Correct Answer(s)
B. B. Stub Flag
D. D. TimersExplanation
In order for OSPF neighbors to establish adjacencies, the fields that have to match between them are the Stub Flag and Timers. The Stub Flag indicates whether a router is configured as a stub router, which affects the way it advertises routes. Timers, on the other hand, determine the intervals at which OSPF neighbors exchange hello packets and other OSPF messages. Matching these fields ensures that the OSPF neighbors have compatible configurations and can communicate effectively.Rate this question:
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- 12.
When OSPF forms adjacencies it has to go through several different states, please organize the following states into the proper order:a. Exstartb. Exchangec. Fulld. Initiale. Loadingf. Two way
Correct Answer(s)
a. Initial b. two way c. Exstart d. Exchange e. Loading f. FullExplanation
The correct order of the OSPF adjacency states is as follows: Initial, Two way, Exstart, Exchange, Loading, Full. In the Initial state, OSPF routers are initialized and ready to begin forming adjacencies. The Two way state is when routers have exchanged hello packets and have confirmed bidirectional communication. The Exstart state is where routers negotiate the master/slave relationship. The Exchange state is when routers exchange link-state database information. The Loading state is when routers request and receive missing link-state information. Finally, the Full state is when routers have a complete and synchronized link-state database.Rate this question:
- 13.
What are the default timer values (Hello & Dead) for OSPF in a LAN environment?
- A.
5 & 20s
- B.
10 & 40s
- C.
15 & 60s
- D.
30 & 120s
Correct Answer
B. 10 & 40sExplanation
The default timer values for OSPF in a LAN environment are 10 seconds for the Hello timer and 40 seconds for the Dead timer. These timers are used to establish and maintain neighbor relationships between OSPF routers. The Hello timer determines how often OSPF routers send hello packets to discover and maintain neighbor relationships, while the Dead timer specifies the amount of time before a router considers a neighbor to be unreachable.Rate this question:
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- 14.
Which of the following is not a purpose of hello packets?
- A.
Change notification
- B.
Neighbor discovery
- C.
Keep alive
- D.
Adjacency formation
Correct Answer
A. Change notificationExplanation
Hello packets are used in network protocols, such as the Routing Information Protocol (RIP) and the Open Shortest Path First (OSPF) protocol, to facilitate communication between network devices. These packets serve several purposes, including neighbor discovery, keep alive, and adjacency formation. However, change notification is not a purpose of hello packets. Change notification typically involves sending specific messages or alerts to notify network devices about changes in the network topology, configuration, or routing tables. Hello packets, on the other hand, are primarily used for initial communication and maintenance tasks within a network.Rate this question:
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- 15.
Designated Router elections occur on which type of networks?
- A.
Point-to-Point Leased line
- B.
Ethernet
- C.
ATM running in NBMA mode
- D.
ATM running in Point-to-Multipoint mode
Correct Answer(s)
B. Ethernet
C. ATM running in NBMA modeExplanation
Designated Router elections occur on Ethernet networks and ATM networks running in NBMA (Non-Broadcast Multiple Access) mode. In Ethernet networks, the Designated Router is responsible for maintaining the Link State Database and flooding Link State Advertisements. In NBMA mode, ATM networks use virtual circuits to connect multiple endpoints, and the Designated Router is elected to optimize the flooding of Link State Advertisements in this type of network.Rate this question:
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- 16.
OSPF supports 5 packet types, what is packet type number 3?
- A.
LSAck
- B.
Hello
- C.
DBD/DDP
- D.
LSR
Correct Answer
D. LSRExplanation
The correct answer is LSR. In OSPF, LSR stands for Link State Request. It is a packet type used to request specific link state information from neighboring routers. When a router needs more information about a particular link state, it sends an LSR packet to the neighboring routers requesting that information. This helps in building and maintaining an accurate and synchronized link state database across the OSPF network.Rate this question:
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- 17.
Which of the following NBMA modes are defined by the OSPF RFC?
- A.
Point-to-Point
- B.
Point-to-Multipoint
- C.
Broadcast
- D.
NBMA
Correct Answer(s)
B. Point-to-Multipoint
D. NBMAExplanation
The OSPF RFC defines two NBMA modes: Point-to-Multipoint and NBMA. Point-to-Multipoint mode allows communication between a single sender and multiple receivers, while NBMA (Non-Broadcast Multiple Access) mode is used for networks where broadcast communication is not possible. The other options, Point-to-Point and Broadcast, are not specifically defined as NBMA modes in the OSPF RFC.Rate this question:
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- 18.
In a multi-access network all devices form full adjacencies
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
In a multi-access network, not all devices form full adjacencies. A multi-access network is a type of network where multiple devices can access the network simultaneously. In this type of network, devices can form either full or partial adjacencies. Full adjacencies are formed between directly connected devices, allowing them to exchange routing information. However, in a multi-access network, devices that are not directly connected may only form partial adjacencies, which restricts the exchange of routing information. Therefore, the statement that all devices in a multi-access network form full adjacencies is false.Rate this question:
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- 19.
On which of the following NBMA network type would static neighbors be required?
- A.
Point-to-Point
- B.
Point-to-Multipoint
- C.
NBMA
- D.
Point-to-Multipoint Non-Broadcast
Correct Answer(s)
C. NBMA
D. Point-to-Multipoint Non-BroadcastExplanation
Static neighbors would be required on an NBMA (Non-Broadcast Multi-Access) network type and on a Point-to-Multipoint Non-Broadcast network type. In both of these network types, there is no automatic neighbor discovery or broadcast capability, so static neighbors need to be manually configured in order for the devices to communicate with each other.Rate this question:
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- 20.
Which of the following commands reflect the correct syntax for defining a static neighbor?
- A.
Router(config-router)#neighbor 1.1.1.1
- B.
Router(config-if)#neighbor 1.1.1.1
- C.
Router(config)#ospf neighbor 1.1.1.1
- D.
Router(config-router)#peer 1.1.1.1
Correct Answer
A. Router(config-router)#neighbor 1.1.1.1Explanation
The correct answer is "Router(config-router)#neighbor 1.1.1.1". This is the correct syntax for defining a static neighbor in a router configuration. The command "neighbor" is used to specify a neighboring router and the IP address "1.1.1.1" is provided as the neighbor's address.Rate this question:
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- 21.
Which are the 2 main functions of the DR?
- A.
Manage LSDB for multi-access segment
- B.
Generate LSA type 2.
- C.
Control authentication requests
- D.
Distribute updates on the multi-access segment.
Correct Answer(s)
B. Generate LSA type 2.
D. Distribute updates on the multi-access segment.Explanation
The two main functions of the DR (Designated Router) are to generate LSA (Link State Advertisement) type 2 and to distribute updates on the multi-access segment. The DR is responsible for maintaining and managing the LSDB (Link State Database) for the multi-access segment. It generates LSA type 2, which contains information about the network's routers and their connections. Additionally, the DR distributes updates to other routers on the multi-access segment, ensuring that all routers have the most up-to-date information about the network topology.Rate this question:
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- 22.
Which 2 parameters assist in DR election?
- A.
IP Address
- B.
Router ID
- C.
Priority
- D.
Code version
Correct Answer(s)
B. Router ID
C. PriorityExplanation
The two parameters that assist in DR (Designated Router) election are the Router ID and Priority. The Router ID is a unique identifier assigned to each router in a network, and it plays a crucial role in the DR election process. The router with the highest Router ID value is elected as the DR. The Priority parameter is used as a tiebreaker in case multiple routers have the same Router ID. The router with the highest Priority value becomes the DR. Therefore, both the Router ID and Priority are important factors in determining the DR in a network.Rate this question:
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- 23.
Which LSAs can’t move between areas?
- A.
Router Link
- B.
Network
- C.
Summary
- D.
External
Correct Answer(s)
A. Router Link
B. NetworkExplanation
Router Link and Network LSAs cannot move between areas because they are local to the area in which they are originated. Router Link LSAs describe the links between routers within an area, while Network LSAs describe the networks connected to a router within an area. These LSAs are not flooded outside of their originating area and are used by routers within the same area to build their routing tables. Summary and External LSAs, on the other hand, can move between areas and are used for inter-area and external routing respectively.Rate this question:
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- 24.
What is the initial age value assigned to an LSA when sent to a neighbor?
- A.
0x00000000
- B.
0x80000000
- C.
0x7fffffff
- D.
0x00000001
Correct Answer
D. 0x00000001Explanation
The initial age value assigned to an LSA when sent to a neighbor is 0x00000001.Rate this question:
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- 25.
Which database is not maintained by OSPF?
- A.
LSDB
- B.
Neighbor Table
- C.
Routing Table
- D.
Recent changes cache
Correct Answer
D. Recent changes cacheExplanation
The recent changes cache is not maintained by OSPF. OSPF, or Open Shortest Path First, is a routing protocol that maintains a Link State Database (LSDB) to store information about the network topology. The LSDB is used to calculate the shortest path to a destination. OSPF also maintains a Neighbor Table to keep track of neighboring routers and a Routing Table to store the best paths to different destinations. However, the recent changes cache is not a part of OSPF's maintenance process.Rate this question:
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- 26.
The cost for an OSPF link increases with link speed.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
The cost for an OSPF link does not increase with link speed. In OSPF, the cost of a link is determined by the bandwidth of the link. The higher the bandwidth, the lower the cost. This is because OSPF aims to choose the shortest path with the highest bandwidth. Therefore, the statement that the cost increases with link speed is false.Rate this question:
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- 27.
Which 2 options reflect valid ways of influencing link costing?
- A.
Router(config-if)#ip ospf cost 100
- B.
Router(config-router)#ip ospf cost 100
- C.
Router(config-if)#auto-cost reference-bandwidth 3000
- D.
Router(config-router)#auto-cost reference-bandwidth 3000
Correct Answer(s)
A. Router(config-if)#ip ospf cost 100
D. Router(config-router)#auto-cost reference-bandwidth 3000Explanation
The correct answer options reflect valid ways of influencing link costing in OSPF. The command "Router(config-if)#ip ospf cost 100" allows the administrator to manually set the cost of a specific interface. On the other hand, the command "Router(config-router)#auto-cost reference-bandwidth 3000" sets the reference bandwidth for calculating the cost of OSPF links based on the bandwidth of the interface. Both options provide a means to influence link costing in OSPF.Rate this question:
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- 28.
DBD packets contain a full copy of the LSDB.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
DBD packets, or Database Description packets, are used in OSPF (Open Shortest Path First) routing protocol. These packets do not contain a full copy of the Link State Database (LSDB). Instead, they contain a summary of the LSDB, including information about the OSPF routers and the network links. The purpose of DBD packets is to exchange information about the LSDB between OSPF routers during the OSPF neighbor discovery process. Therefore, the correct answer is False.Rate this question:
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- 29.
An OSPF router with only point-to-point leased lines can’t generate this type of LSA.
- A.
Router link
- B.
Network Link
- C.
Summary Link
- D.
External Link
Correct Answer
B. Network LinkExplanation
An OSPF router with only point-to-point leased lines cannot generate a "Network Link" type of LSA. This is because a "Network Link" LSA is used to advertise the presence of a multi-access network, such as an Ethernet LAN, to other routers in the OSPF area. Since point-to-point leased lines are not considered multi-access networks, the OSPF router cannot generate this type of LSA to advertise its presence.Rate this question:
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- 30.
What is the initial sequence number used for all LSAs?
- A.
0x00000000
- B.
0x80000001
- C.
0x00000001
- D.
0x80000000
Correct Answer
D. 0x80000000Explanation
The initial sequence number used for all LSAs is 0x80000000.Rate this question:
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- 31.
Regarding External LSAs please pick the correct responces.
- A.
External Type 2 doesn’t increment normally in the internal network.
- B.
External Type 1 increments normally within the internal network.
- C.
External Type 2 increments normally within the internal network.
- D.
External Type 1 doesn’t increment normally in the internal network.
Correct Answer(s)
A. External Type 2 doesn’t increment normally in the internal network.
B. External Type 1 increments normally within the internal network.Explanation
External Type 2 LSAs do not increment normally in the internal network because they have a higher administrative distance and are considered less trustworthy than internal LSAs. On the other hand, External Type 1 LSAs do increment normally within the internal network because they have a lower administrative distance and are considered more trustworthy.Rate this question:
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- 32.
With relation to lab diagram 4, which commands reflect valid commands to configure PXR1 to function as an ABR? (Diagram)
- A.
Router(config-router)#network 10.1.1.0 255.255.255.0 area 0
- B.
Router(config-router)#network 10.1.1.0 0.0.0.255 area 0.0.0.0
- C.
Router(config-router)#network 192.168.1.0 255.255.255.0 area 1.0.0.0
- D.
Router(config-router)#network 192.168.1.0 0.0.0.255 area 1
Correct Answer(s)
A. Router(config-router)#network 10.1.1.0 255.255.255.0 area 0
B. Router(config-router)#network 10.1.1.0 0.0.0.255 area 0.0.0.0Explanation
Based on the OSPF lab diagram provided, the correct commands to configure PXR1 (which functions as an Area Border Router or ABR, connecting Area 0.0.0.0 and Area 1.0.0.0) are as follows:
Router(config-router)#network 10.1.1.0 0.0.0.255 area 0
This command correctly assigns the network 10.1.1.0/24 to Area 0.
Router(config-router)#network 192.168.1.0 0.0.0.255 area 1
This command correctly assigns the network 192.168.1.0/24 to Area 1.
These commands reflect the valid OSPF configuration necessary to set up PXR1 as an ABR, enabling it to route traffic between Area 0 and Area 1.Rate this question:
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- 33.
The LSDB for routers that belong to the same are is _____________.
- A.
Unique
- B.
Identical
- C.
None of the Above
Correct Answer
B. IdenticalExplanation
The LSDB (Link State Database) for routers that belong to the same area is identical. This means that all routers within the same area have the same information about the network topology. Each router maintains its own copy of the LSDB, which is built based on the link state advertisements received from other routers in the area. By having identical LSDBs, routers can make consistent routing decisions and ensure efficient communication within the area.Rate this question:
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- 34.
Pick to appropriate LSDB lifetime values.
- A.
MaxAge – 30 min
- B.
LSA Refresh – 15 min
- C.
MaxAge – 60 min
- D.
LSA Refresh – 30 min
Correct Answer(s)
C. MaxAge – 60 min
D. LSA Refresh – 30 minExplanation
The MaxAge value determines the maximum time a router will keep a received LSA before discarding it. In this case, the MaxAge value of 60 minutes indicates that the router will keep the LSA for up to 60 minutes before considering it outdated. The LSA Refresh value determines the time interval after which a router will regenerate and flood its own LSAs. A value of 30 minutes means that the router will refresh and flood its LSAs every 30 minutes. Therefore, the given answer of MaxAge – 60 min and LSA Refresh – 30 min is appropriate.Rate this question:
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- 35.
Which LSAs might exist in a single area OSPF design?
- A.
Router link
- B.
Network Link
- C.
Summary Link
- D.
External Link
Correct Answer(s)
A. Router link
B. Network Link
D. External LinkExplanation
In a single area OSPF design, there are several types of Link State Advertisements (LSAs) that might exist. These include Router links, which are used to advertise the links of the router itself within the area. Network links are used to advertise the links of the networks connected to the router within the area. External links are used to advertise routes from other routing domains or autonomous systems. Therefore, in a single area OSPF design, the LSAs that might exist are Router links, Network links, and External links.Rate this question:
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- 36.
How does OSPF represent a numbered point-to-point link in the LSDB?
- A.
Transit link
- B.
Stub Link
- C.
Point-to-point link
- D.
Virtual link
Correct Answer(s)
B. Stub Link
C. Point-to-point linkExplanation
OSPF represents a numbered point-to-point link in the LSDB as either a Stub Link or a Point-to-point link. A Stub Link is a link that connects a router to a network, but does not have any other routers connected to it. A Point-to-point link, on the other hand, is a direct link between two routers. Both of these representations are used in OSPF to accurately depict the topology of the network in the LSDB.Rate this question:
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- 37.
In the diagram what is the link count for P1R1? (Diagram)
- A.
2
- B.
3
- C.
4
- D.
5
Correct Answer
D. 5 -
- 38.
Which command is used to view the detail router link entries in the LSDB?
- A.
Show ospf router
- B.
Show ip ospf router
- C.
Show ip ospf database
- D.
Show ip ospf database router
Correct Answer
D. Show ip ospf database routerExplanation
The "Show ip ospf database router" command is used to view the detailed router link entries in the Link State Database (LSDB) for OSPF. This command specifically displays information related to OSPF routers in the database. By using this command, network administrators can get a comprehensive view of the OSPF routers and their link information within the network.Rate this question:
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- 39.
What is the maximum age that an OSPF LSA can reach in seconds?
- A.
86000
- B.
1200
- C.
3600
- D.
4800
Correct Answer
C. 3600Explanation
The maximum age that an OSPF LSA (Link State Advertisement) can reach is 3600 seconds. This refers to the amount of time that an LSA can remain in the OSPF database before it is considered expired and removed.Rate this question:
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- 40.
What address represents all OSPF DR devices?
- A.
224.0.1.39
- B.
224.0.0.5
- C.
224.0.0.6
- D.
224.1.0.6
Correct Answer
C. 224.0.0.6Explanation
The address 224.0.0.6 represents all OSPF DR (Designated Router) devices. This address is a multicast address used by OSPF (Open Shortest Path First) to send OSPF hello packets to the designated routers in a network. The designated router is responsible for maintaining the OSPF database and exchanging routing information with other routers in the network. Therefore, 224.0.0.6 is the correct address for OSPF DR devices.Rate this question:
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- 41.
How many Network LSA entries will exist in the diagram?
- A.
1
- B.
2
- C.
3
- D.
None of the above
Correct Answer
D. None of the above -
- 42.
Which of the following commands will enable OSPF on the Ethernet link on P1R1?
- A.
Router(config-if)#network 10.0.0.0 255.255.255.0 area 0
- B.
Router(config-router)#network 10.0.0.0 255.255.255.0 area 0
- C.
Router(config-router)#network 10.1.1.0 0.0.0.255 area 0
- D.
Router(config-if)#network 10.1.1.0 0.0.0.255 area 0
Correct Answer
C. Router(config-router)#network 10.1.1.0 0.0.0.255 area 0Explanation
This command is the correct answer because it enables OSPF on the Ethernet link on P1R1. The "network" command is used to specify which networks are participating in OSPF. In this case, the command "network 10.1.1.0 0.0.0.255 area 0" is used to enable OSPF on the Ethernet link with the IP address range of 10.1.1.0 to 10.1.1.255 and assigns it to area 0.Rate this question:
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- 43.
Which command should be used to determine which area an interface belongs to?
- A.
Show ip ospf
- B.
Show ip protocols
- C.
Show ip route
- D.
Show ip ospf interface
Correct Answer
D. Show ip ospf interfaceExplanation
The correct answer is "Show ip ospf interface." This command is used to determine which area an interface belongs to in OSPF (Open Shortest Path First) routing protocol. By using this command, the user can view the OSPF interface information, including the area ID to which the interface is assigned. It provides details about the OSPF process, such as the router ID, network type, and area ID, helping in troubleshooting and verifying the OSPF configuration.Rate this question:
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- 44.
What priority will, when assigned to an OSPF device ensure that it will not become a DR?
- A.
0
- B.
1
- C.
2
- D.
3
- E.
255
Correct Answer
A. 0Explanation
A priority of 0, when assigned to an OSPF device, ensures that it will not become a DR (Designated Router). In OSPF, the DR is responsible for managing communication between multiple routers in a broadcast network. The router with the highest priority becomes the DR, and if multiple routers have the same priority, the router with the highest router ID is selected. By assigning a priority of 0, the device is effectively removing itself from consideration as a DR, allowing other routers with higher priorities to take on that role.Rate this question:
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- 45.
On a multi-access network, what is the neighbor state between non-DR devices?
- A.
Full
- B.
Initial
- C.
2-way
- D.
No state exists
Correct Answer
C. 2-wayExplanation
In a multi-access network, the neighbor state between non-DR (Designated Router) devices is the 2-way state. This state indicates that the devices have established bidirectional communication and are ready to exchange routing information. The 2-way state is a prerequisite for forming neighbor relationships and participating in the OSPF (Open Shortest Path First) routing protocol.Rate this question:
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- 46.
Given the following output, which kind of devices it this?
- A.
DR
- B.
BDR
- C.
Non-DR
- D.
Not able to determine that from this output
Correct Answer
B. BDRExplanation
The given output is related to networking devices in a network. BDR stands for Backup Designated Router, which is a role assigned to a router in a network that acts as a backup to the Designated Router (DR). The DR and BDR are responsible for maintaining the network topology and exchanging routing information. Therefore, the correct answer suggests that the output represents a BDR device in the network.Rate this question:
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- 47.
What is the default administrative distance for OSPF?
- A.
90
- B.
100
- C.
110
- D.
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 to determine which route should be preferred if multiple routing protocols provide information about the same destination network. A lower administrative distance indicates a higher priority. In the case of OSPF, its default administrative distance of 110 is lower than other routing protocols like RIP (120) and EIGRP (90), making OSPF routes preferred over them.Rate this question:
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- 48.
What command would be usefull to determine why OSPF is not forming adjacencies?
- A.
A. Debug ip ospf packet
- B.
B. Debug ip ospf events
- C.
C. Debug ip ospf
- D.
D. Debug ip ospf adj
Correct Answer
D. D. Debug ip ospf adjExplanation
The command "Debug ip ospf adj" would be useful to determine why OSPF is not forming adjacencies. This command enables debugging for OSPF adjacency events, allowing the user to view detailed information about the OSPF neighbors and any errors or issues that may be preventing the formation of adjacencies. By analyzing the output of this command, network administrators can troubleshoot and identify the root cause of the problem.Rate this question:
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- 49.
Data that needs to travel from a non-backbone area to another non-backbone area will always use the fastest physical link to get there with OSPF.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
Data that needs to travel from a non-backbone area to another non-backbone area in OSPF does not always use the fastest physical link to get there. OSPF uses a routing algorithm based on the cost of the link, which takes into account factors such as bandwidth, delay, and reliability. The shortest path is determined based on the cumulative cost of the links along the path, not just the physical link speed. Therefore, the statement is false.Rate this question:
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- 50.
An ASBR is able to inject external protocol information into all areas.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
An ASBR (Autonomous System Boundary Router) is not able to inject external protocol information into all areas. ASBRs are routers that connect different autonomous systems and exchange routing information between them. They are responsible for injecting external routes into the local routing domain, but this information is not automatically propagated to all areas within the domain. Instead, ASBRs typically inject external routes into a specific area or areas based on the network design and routing policies in place. Therefore, the statement that an ASBR can inject external protocol information into all areas is false.Rate this question:
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Aug 30, 2024Quiz Edited by
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Mar 01, 2011Quiz Created by
Apalani