Posted in CCNA 2 - Routing Protocols and Concepts (V4.0) - 19 April 2010 - 2 comments - 74,580 views
1. What action does a link-state router take immediately upon receipt of an LSP from a neighboring router?
floods the LSP to neighbors
calculates the SPF algorithm
runs the Bellman-Ford algorithm
computes the best path to the destination network
2. Why is it difficult for routing loops to occur in networks that use link-state routing?
Each router builds a simple view of the network based on hop count.
Routers flood the network with LSAs to discover routing loops.
Each router builds a complete and synchronized view of the network.
Routers use hold-down timers to prevent routing loops.
3.
Refer to the exhibit. What kind of information would be seen in an LSP sent from router JAX to router ATL?
hop count
uptime of the route
cost of the link
a list of all the routing protocols in use
4. To achieve network convergence, what three steps does each link state router take? (Choose three.)
use automatic summarization to reduce the size of routing tables
build a Link State Packet (LSP) containing the state of each directly connected link
flood the LSP to all neighbors, who then store all LSPs received in a database
discover neighbors and establish adjacencies using the hello packet sent at regular intervals
construct a complete map of the topology and compute the best path to each destination network
use the DUAL FSM to select efficient, loop-free paths, and insert routes into the routing table
5.
Refer to the exhibit. When Router D is configured to use a link-state routing protocol and is added to the network, what is the first thing that it does to begin learning the network topology?
It sends LSP packets to Routers B and C.
It sends LSP packets to all routers in the network.
It sends Hello packets to all routers in the network.
It sends information about its directly connected neighbors to Routers A and E.
It sends information about its directly connected neighbors to all routers in the network.
It learns about its directly connected networks when its interfaces reach the up state.
6. 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?
RIP version 2
IGRP
EIGRP
OSPF
BGP
7. What two events will cause a link state router to send LSPs to all neighbors? (Choose two.)
30 second timer expires
whenever the network topology changes
immediately after the Bellman-Ford algorithm has run
immediately after the DUAL FSM has built the topology database
upon initial startup of router or routing protocol
8. What is the final step in the link state routing process?
successors are placed into the routing table
SPF computes best path to each destination network
LSPs are flooded to all neighbors to converge the network
DUAL algorithm is run to find best path to destination networks
9.
Refer to the exhibit. What does JAX do with link-state packets from ORL?
sends out its updated routing table to both ORL and BOS routers
sends out the individual link-state packets out the interface connected to BOS
queries BOS to see if it has a better route
only adds it to the local routing table and performs no other actions
10. What two statements correctly describe the link state routing process? (Choose two.)
each router in the area floods LSPs to all neighbors
all routers in the area have identical link state databases
LSPs use the reserved multicast address of 224.0.0.10 to reach neighbors
routing loops are prevented by running the Diffusing Update Algorithm (DUAL)
Reliable Transport Protocol (RTP) is the protocol used by for the delivery and reception of LSPs
11. Which database or table must be identical on all link-state routers within an area in order to construct an accurate SPF tree?
routing table
adjacency table
link-state database
neighbor table
topology database
12.
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?
BOS -> ATL because this path is the least hops
BOS -> ATL because this path is highest cost
BOS -> ORL -> JAX -> ATL because this path is the lowest cost
traffic would load balance across all links
13. What feature do modern link-state protocols provide to minimize processing and memory requirements?
splitting routing topologies into smaller areas
assigning lower process priorities to route calculations
using update timers to restrict routing updates
strict split horizon rules to reduce routing table entries
14. What speeds up convergence in a network using link-state routing?
updates triggered by network changes
updates sent at regular intervals
updates sent only to directly connected neighbors
updates that include complete routing tables
15. Which algorithm is run by link-state routing protocols to calculate the shortest path to destination networks?
DUAL
Dijkstra
Bellman-Ford
Diffie-Hellman
16. What are some of the advantages of using a link-state routing protocol instead of a distance vector routing protocol? (Choose two.)
The topology database eliminates the need for a routing table.
Frequent periodic updates are sent to minimize the number of incorrect routes in the topological database.
Routers have direct knowledge of all links in the network and how they are connected.
After the inital LSA flooding, they generally require less bandwidth to communicate changes in a topology.
Link-state protocols require less router processor power than distance vector protocols.
17.
Refer to the exhibit. If all routers and interfaces are configured to use a link-state routing protocol, from which routers will router D receive hello packets?
A and E
B and C
A, B, C, and E
C only
18. Which two routing protocols use Dijkstra’s shortest path first algorithm? (Choose two.)
RIPv1
RIPv2
IS-IS
19. When are link-state packets sent to neighbors?
every 30 seconds
every 180 seconds
after the holddown time expires
when a link goes up or down
when a routing loop occurs
20. What are two advantages of using a link-state routing protocol instead of a distance vector routing protocol? (Choose two.)
Each router independently determines the route to each network.
After the inital LSP flooding, they generally require less bandwidth to communicate changes in a topology.
21. To achieve network convergence, what three steps does each link state router take? (Choose three.)
send hello packages at regular intervals to discover neighbors and establish adjacencies
Posted in CCNA 2 - Routing Protocols and Concepts (V4.0) - 20 April 2010 - 8 comments - 90,867 views
1.
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?
2
156
1564
1785
1787
2.
Refer to the exhibit. Router1 and Router2 are running OSPF. The show ip ospf neighbor command reveals no neighbors. What is a possible cause?
OSPF autonomous system IDs do not match.
OSPF process IDs do not match.
OSPF network types are identical.
OSPF hello or dead timers do not match.
3. 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?
All routes for the entire network will be present.
Directly connected networks that are operational will be in the routing table.
Because the SPF algorithm has not completed all calculations, no routes will be in the table.
A summary route for all previously learned routes will automatically appear in the routing table until all LSPs have been received by the router.
4.
Refer to the exhibit. What configuration statements would give the results that are shown in the output of the show ip protocols command?
B(config)# int fa0/0 B(config-if)# router-id 192.168.1.5
B(config)# int lo0 B(config-if)# ip address 192.168.1.5
B(config)# router ospf 1 B(config-router)# router-id 192.168.1.5
B (config)# router ospf 1 B(config-router)# ip address 192.168.1.5
Refer to the exhibit. When OSPF is operational in the exhibited network, what neighbor relationship is developed between Router1 and Router2?
A FULL adjacency is formed.
A 2WAY adjacency is formed.
Router2 will become the DR and Router1 will become the BDR.
Both routers will become DROTHERS.
6. What does OSPF use to calculate the cost to a destination network?
bandwidth
bandwidth and hop count
bandwidth and reliability
bandwidth, load, and reliablity
7.
Refer to the exhibit. The routers in the exhibit are using default OSPF configuration settings to advertise all attached networks. If all of the routers start at the same time, what will be the result of the DR and BDR elections for this single area OSPF network? (Choose three.)
HQ will be DR for 10.4.0.0/16.
Router A will be DR for 10.4.0.0/16.
HQ will be BDR for 10.4.0.0/16.
Router A will be DR for 10.5.0.0/16.
Remote will be DR for 10.5.0.0/16.
Remote will be BDR for 10.5.0.0/16.
8. What does OSPF use to reduce the number of exchanges of routing information in networks where large numbers of neighbors are present? (Choose two.)
root router
backup root router
domain router
backup domain router
designated router
backup designated router
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?
Router C cannot win a DR election under any circumstances.
If the link for interface 192.168.1.4 goes down, router B will become the new DR.
The highest router ID was most likely determined via an OSPF router-id statement or statements.
If a new router is added with a higher router ID than router D, it will become the DR.
10.
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?
B(config-router)# network 192.168.1.0 0.0.0.3 area 0
B(config-router)# network 10.16.1.0 0.0.0.224 area 0
B(config-router)# network 10.16.1.0 255.255.255.224 area 0
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
11.
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.)
DR for network 192.168.1.200
BDR for network 192.168.1.200
DROTHER on 192.168.1.200
DR for network 192.168.1.204
BDR for network 192.168.1.204
DROTHER on network 192.168.1.204
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 will become the DR. D will become the BDR.
A will become the DR. C will remain the BDR.
D will remain the DR. A will become the BDR.
D will remain the DR. C will remain the BDR.
13. 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?
192.168.0.0/24 through 192.168.0.15/24
192.168.0.0/24 through 192.168.15.0/24
192.168.15.0/24 through 192.168.31.0/24
192.168.15.0/24 through 192.168.255.0/24
192.168.16.0/24 through 192.168.255.0/24
14.
Refer to the exhibit. RouterA, RouterB, and RouterC in the diagram are running OSPF on their Ethernet interfaces. Router D was just added to the network. Routers are configured with the loopback interfaces (Lo 0) that are shown in the exhibit. What happens to the OSPF DR/BDR after RouterD is added to the network?
RouterB takes over as DR and RouterD becomes the BDR.
RouterD becomes the BDR and RouterA remains the DR.
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