Connecting Networks (Version 6.00) – CN SIC Chapter 3
QUESTION 1
Which action should be taken when planning for redundancy on a hierarchical network design?
Implement STP PortFast between the switches on the network.
Immediately replace a nonfunctioning module, service, or device on a network.
Purchase backup equipment for every network device at the distribution layer.
Add alternate physical paths for data to traverse the network.*
One method of implementing redundancy is path redundancy, which means installing alternate physical paths for data to traverse the network. Redundant links in a switched network support high availability and can be used for load balancing, thus reducing congestion on the network.
QUESTION 2
Refer to the exhibit. Suppose that routers B, C, and D have a default priority, and router A has a priority 0. Which conclusion can be drawn from the DR/BDR election process?
Router A will become the DR and router D will become the BDR.
If the priority of router C is changed to 255, then it will become the DR.
If the DR fails, the new DR will be router B.*
If a new router with a higher priority is added to this network, it will become the DR.
If the priority is set to 0, the router is not capable of becoming the DR, so router A cannot be the DR. OSPF DR and BDR elections are not preemptive. If a new router with a higher priority or higher router ID is added to the network after the DR and BDR election, the newly added router does not take over the DR or the BDR role.
QUESTION 3
A network administrator is troubleshooting the EIGRP routing between two routers, R1 and R2. The problem is found to be that only some, but not all networks attached to R1 are listed in the routing table of router R2. What should the administrator investigate on router R1 to determine the cause of the problem?
Do the network commands include all the networks to be advertised?*
Does the hello interval setting match the hello interval on R2?
Does the AS number match the AS number on R2?
Is the interface connected to R2 configured as a passive interface?
The fact that some networks appear in the routing table of R2 indicates that there is basic EIGRP communication between R1 and R2. This excludes the possibility of AS number mismatch and the interface between R1 and R2 being passive. Hello interval timers between EIGRP routers do not have to match. The administrator needs to make sure that the network commands cover all networks attached to R1 that should be advertised.
QUESTION 4
Fill in the blank.
EIGRP keeps feasible successor routes in the _____ table.
Correct Answer: topology*
EIGRP maintains a topology table that contains all of the routes learned from EIGRP neighbors. The routes will include successors and feasible successors.
QUESTION 5
Refer to the exhibit. On which router or routers would a default route be statically configured in a corporate environment that uses single area OSPF as the routing protocol?
R0-B and R0-C
ISP, R0-A, R0-B, and R0-C
ISP
R0-A*
R0-A, R0-B, and R0-C
ISP and R0-A
The default route is applied to the router that connects to the Internet, or R0-A. R0-A then distributes that default route using the OSPF routing protocol.
QUESTION 6
Refer to the exhibit. What will Router1 do if it receives packets that are destined to network 172.16.4.0/24?
forward the packets to the gateway of last resort
drop the packets*
send the packets to network 0.0.0.0
send the packets out interface GigabitEthernet 0/0
In this example Router1 does not have a specific route to the172.16.4.0/24 network. Because the 172.16.4.0/24 network falls within the 172.16.0.0/18 summary network route to Null0, this route will be chosen. As a consequence, Router1 will drop the packets destined for the 172.16.4.0/24network. The reason for Router1 not using the default route is that the Null0 route has a longer matching network mask.
QUESTION 7
In a large enterprise network, which two functions are performed by routers at the distribution layer? (Choose two.)connect users to the network
provide a high-speed network backbone
connect remote networks*
provide Power over Ethernet to devices
provide data traffic security*
In a large enterprise network, the provision of a high-speed network backbone is a function of the core layer. Access layer switches connect users to the network and provide Power over Ethernet to devices. Distribution layer routers provide data traffic security and connections to other networks.
QUESTION 8
Which two metric weights are set to one by default when costs in EIGRP are being calculated? (Choose two.)
k6
k4
k2
k1*
k5
k3*
By default, k1 and k3 are set to one and k2, k4, and k5 are set to zero during cost calculation by the EIGRP process. There is no k6 value.
QUESTION 9
Open the PT Activity. Perform the tasks in the activity instructions and then answer the question.
Which message was displayed on the web server?Work done!
Congratulations!
You’ve made it!*
Wonderful work!
The three routers R1, R2 and R3 implement EIGRP as the routing protocol. There are two discontiguous networks with no connectivity between them. Automatic summarization is enabled by default on routers R1 and R2, and this is causing a routing problem between discontiguous networks. The solution is to issue the no auto-summary command on each router:
R1(config)# router eigrp 100
R1(conf-router)# no auto-summary
R2(config)# router eigrp 100
R2(conf-router)# no auto-summary
After these commands are issued, PC1 is able to access the web server and the message displayed is “You’ve made it!”.
QUESTION 10
An administrator is troubleshooting an adjacency issue between two OSPFv3 routers. Which two neighbor states indicate a stable adjacency between the routers? (Choose two.)
2way*
full*
loading
exstart
exchange
The full and 2way states are two stable OSPF adjacency types.