ITT562 Routing Protocols And Concepts JUNE 2012.

CONFIDENTIAL CS/JUN 2012/ITT552/562

UNIVERSITI TEKNOLOGI MARA FINAL EXAMINATION

COURSE *

COURSE CODE

EXAMINATION

TIME

SWITCHING TECHNOLOGY/ROUTING PROTOCOLS AND CONCEPTS

ITT552/562

JUNE 2012

3 HOURS

INSTRUCTIONS TO CANDIDATES

1. This question paper consists of two (2) parts : PART A (25 Questions)

PART B (4 Questions)

2. Answer ALL questions from all two (2) parts :

i) Answer PART A in the Objective Answer Sheet. ii) Answer PART B in the Answer Booklet. Start each answer on a new page.

3. Do not bring any material into the examination room unless permission is given by the invigilator.

4. Please check to make sure that this examination pack consists of :

i) the Question Paper ii) an Answer Booklet - provided by the Faculty iii) an Objective Answer Sheet - provided by the Faculty

DO NOT TURN THIS PAGE UNTIL YOU ARE TOLD TO DO SO

This examination paper consists of 11 printed pages © Hak Cipta Universiti Teknologi MARA CONFIDENTIAL

CONFIDENTIAL 2 CS/JUN 2012/ITT552/562

PART A (25 MARKS)

1. Which statements are not true regarding distance vector routing protocol?

A. Routing updates are broadcast at intervals. B. Hop counts can be used for path selection. C. EIGRP can do unequal-cost load balancing. D. RIPvl multicast its routing updates.

2. What is routing loop? '

A. A condition where a return path from a destination is different from the outbound path forming a "loop",

B. A condition where a packet is constantly transmitted within a series of routers without ever reaching its intended destination.

C. A packet bouncing back and forth between two loopback interfaces on a route. D. The distribution of routes from one routing protocol into another.

3. allows RIP to avoid routing loops by advertising a metrics of infinity.

A. Split horizon B. Route poisoning C. Maximum hop count D. Hold-down timer

4. Refer to Figure 1. What is the administrative distance of the route to the 189.80.3.0 network?

<output omitted> C 189.80.1.0 is directly connected, FastEthernetO/0 C 189.80.2.0 is directly connected, Serial0/0/0 R 189.80.3.0 [120/1] via 189.80.2.2, 00:00:05, Serial0/0/0 <output omitted>

Figure 1

A. 1 B. 12 C. 24 D. 120

5. A network administrator is troubleshooting an EIGRP problem on a router and needs to confirm the IP addresses of the devices with which the router has established adjacency. The retransmit interval and the queue counts for the adjacent routers also need to be checked. What command will display the required information?

A. Router# show ip eigrp topology B. Router# show ip eigrp interfaces C. Router# show ip eigrp adjacency D. Router# show ip eigrp neighbors

© Hak Cipta Universiti Teknologi MARA CONFIDENTIAL


6. Refer to Figure 2. EIGRP is configured on all routers in the network. On a basis of the show i p e i g r p topo logy output provided, what conclusion can be derived?

Rl# show i p e i g r p topology

<output omit ted>

P 1 0 . 1 . 2 . 0 / 2 4 , 1 s u c c e s s o r s , FD i s 281600 v i a Connected, Fas tE the rne t 0/0

A 10 .6 .1 .0 /24 , , 0 s u c c e s s o r s , FD i s 3385160704, Q 1 r e p l i e s , a c t i v e 00 :00 :41 , q u e r y - o r i g i n : Local o r i g i n Remaining r e p l i e s :

v i a 1 0 . 1 . 2 . 1 , r , Fas tEthernetO/0

Figure 2

A. Router R1 can send traffic destined for network 10.6.1.0/24 out of interface FastEthernetO/0.

B. Router R1 is waiting for a reply from the neighbor 10.1.2.1 to the hello message sent out before it declares the neighbor unreachable 0.0.0.0/0 via 192.168.0.1.

C. Router R1 is waiting for a reply from the neighbor 10.1.2.1 to the hello message sent out inquiring for a second successor to network 10.6.1.0/24.

D. Router R1 is waiting for a reply from the neighbor 10.1.2.1 in response to the query sent out about network 10.6.1.0/24.

7. What will a router do if it does not have EIGRP feasible successor route to a destination network and the successor route to that destination network is in active status?

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

B. It routes all traffic that is addressed to the destination network to the interface indicated in the routing table.

C. It sends a multicast query packet to all adjacent neighbors requesting available routing paths to the destination network.

D. It sends a copy of its neighbor table to all adjacent routers.

8. As a Cisco technician, you need to know EIGRP protocol very well. Which of the following is true about EIGRP successor routes?

A. Successor route is used by EIGRP to forward traffic to a destination. B. Successor routes are saved in the topology table to be used if the primary route fails. C. Successor routes are flagged as "active" in the routing table. D. A successor route will not be backed up by a feasible successor route.


CONFIDENTIAL CS/JUN 2012/ITT552/562

9. The company uses EIGRP as the routing protocol.

192.168.10.64/26 192.168.10.192/26

192.168.10.0/30 192.168.10.4/30

192.168.10.128/26

R3# show i p rou t e Gateway of l a s t r e s o r t i s not s e t 192 168 .10 .0 /24 i s v a r i a b l y subne t t ed , 6 subne t s , 2 masks D 192.168. 10.64/26 [90/2195456] v i a 192 .168 .10 .9 , 00 :03 :31 , S e r i a l 0 / 0 D 192 .168 .10 .0 /30 [90/2681856] v i a 192 .168 .10 .9 , 00 :03 :31 , S e r i a l 0 / 0 C 192.168.10.4/30 is directly connected, Serial 0/1 C 192.168.10.8/30 is directly connected, Serial 0/0 C 192.168.10.192/26 is directly connected, FastEthernet0/0 D 192.168.10.128/26 [90/2195456] via 192.168.10.5,00:03 31, Serial 0/1

What path will packets take from a host on 192.168.10.192/26 network to a host on LAN attached to router R1?

the

A. The path of the packets will be R3 to R2 to R1. B. The path of the packets will be R3 to R1 to R2. C. The path of the packets will be both R3 to R2 to R1 and R3 to R1. D. The path of the packets will be R3 to R1.

10. A router has learned three possible routes that could be used to reach a destination network. One route is from EIGRP and has a composite metric of 20514560. Another route is from OSPF with a metric of 782. The last is from RIPv2 and has a metric of 4. Which route or routes will the router install in the routing table?

A. The OSPF route. B. The EIGRP route. C. The RIPv2 route. D. The OSPF and RIPv2 routes.



11. Which of the following are not regards to RIPvl characteristic?

A. Uses hop count as a metric. B. Considers a metric of 16 as infinity. C. Has an administrative distance of 110 by default. D. Calculates metrics using the Bellman Ford algorithm.

12. Passive interface can be implemented to prevent ?

A. Confusion if both RIPvl and RIPv2 are being advertised on a network. B. Wasted bandwidth and processing from unnecessary updates. C. Updates from being sent out without a password. D. Routing loops.

13. What is the reason to implement RIPv2 rather than RIPvl?

A. Used RIPv2 supports multi-areas. B. RIPv2 supports more than 16 routers. C. RIPv2 supports routing update authentication. D. RIPv2 supports classful (and not classless) routing.

14. What is the command to disable automatic summarization in RIPv2?

A. Router(config)#no auto-summary B. Router(config-router)# no auto-summary C. Router(config-if)#no auto-summary D. Not recommended to disable automatic summarization.

15. The network 182.16.192.0 with a mask of 255.255.240.0 will support

A. 256 stations B. 1024 stations C. 4094 stations D. 1022 stations

16. How many hosts could be supported on a 22 bit network?

A. 22 B. 1022 C. 4094 D. 512

17. Which of the following devices share the same network?

A. 192.168.78.25/29 and 192.168.78.23/29. B. 192.168.78.23/29 and 192.168.78.33/29. C. 192.168.78.33/29 and 192.168.78.38/29. D. 192.168.78.38/29 and 192.168.78.41/29.



18. A network administrator has enabled RIP on routers B and C in Figure 3. Which of the following commands will prevent RIP updates from being sent to Router A?

Figure 3

A. A(config)# router rip A(config-router)# passive-interface SO/0

B. B(config)# router rip B(config-router)# network 192.168.25.48 B(config-router)# network 192.168.25.64

C.A(config)# router rip A(config-router)# no network 192.168.25.32

D.B(config)# router rip B (config-router)# passive-interface SO/0

19. Which of the following about Routing Protocols is correct?

A. The RIP 2 is a Distance Vector Protocol. B. The RIP 1 uses bandwidth and delay as the metric. C. RIP 1 uses subnet mask. D. The hold down timer value for RIP is 240 sec.

20. What is the maximum number of hops that OSPF allows before marking a network as unreachable?

A. 15 B. 16 C. 255 D. Unlimited.

21. Which command must be entered when connecting two routers without external DCE devices via a serial link?

A. Serial up. B. DTE rate. C. DCE rate. D. Clockrate.



22. R1 in A network engineer is configuring a new router. The interfaces have been configured with IP addresses and activated, but no routing protocols or static routes have been configured yet. What routes are present in the routing table?

A. Default routes. B. Broadcast routes. C. Direct connections. D. No routes; the routing table is empty.

23. Which routing principle is correct?

A. If one router has certain information in its routing table, all adjacent routers have the same information.

B. Routing information about a path from one network to another implies routing information about the reverse or return path.

C. Every router makes its routing decision alone, based on the information it has in its own routing table.

D. Every router makes its routing decisions based on the information it has in its own routing table and its neighbor routing tables.

24. What could be the rationale behind using p a s s i v e - i n t e r f a c e command when configuring a router?

A. Allows interfaces to share common IP addresses. B. Allows an interface to remain up without the aid of keepalives. C. Allows a router to send routing and not receive updates via that interface. D. Allows a router to receive routing updates on an interface but not send updates via

that interface.

25. When presented with multiple valid routes to a destination, what criteria does a router use to determine which routes to add to the routing table?

A. The router selects the routes with the best metric. All routes that have the same best metric are added to the routing table.

B. The router first selects routes with the lowest administrative distance. The resulting routes are then prioritized by metric and the routes with the best metric are added to the routing table.

C. The router selects the routes with the lowest administrative distance. All routes with the same lowest administrative distance are added to the routing table.

D. The router installs all routes in the routing table but uses the route with the best metric most when load balancing.



PART B (75 MARKS)

QUESTION 1

a) Router A in Figure 1 is not receiving the routes from Router B about network 192.168.3.16. Figure 2 shows the configurations for Router A and B. You try to run #debug i p e i g r p command on Router B and the output display:

IP-EIGRP: 192.168.3 .16/28 - denied by d i s t r i b u t e l i s t IP-EIGRP: 192.168.3 .16/28 - do not a d v e r t i s e out Ser ia lO IP-EIGRP: 192 .168 .3 .0 / - do a d v e r t i s e out S e r i a l

As a network engineer, you are responsible to troubleshoot this problem. You believe that there are two possible reasons for this. One is due to misconfigured network number and the other reason could be manual or auto-summarization across major network boundary. Explain your thought and give TWO (2) possible solutions to this problem.

192.168.3.33/28 Update rejected by Router A

192.168.3.16

Sending update 192.168.3.21/28 ' 192.168.3.0/24

Figure 1

Router A# interface etherriet 0 ip address 172.16.3.1 255.255.255.0

interface serial 0 : ip address 10.1.1.1 255.255.255,0 router eigrp 1

network 172.l&vO.O ,.;/. network 10.0.0.0:

Router B# interface ethernet 0 H ip •address:: 192 .168 , 3.17 255 .255, 255 ,240 interface:" serial:: 0 .:•; : ; ;ip;;: addres s : lu:.l M . 2/ 2 55 .255 .255 . 0 : ; router eigrp Tl /.'.

• ::netwbE:f:k ::i;€i::.:;©;. GiJQ":&

: v-distcibute-l^ access-list 1 permit 192.168.3.160 0.0.0.15

Figure 2 (8 marks)



b) State ONE (1) reason why link state routing protocols require lots of memory. (1 mark)

c) Your are required to solve EIGRP Neighbor Problem below:

i) RTR A and RTR B Autonomous System (AS) number have been configured as shown in Figure 3. However, no EIGRP neighbor relationship is formed between the two routers. What could be the reason? Show the step to resolve the problem.

RTR B#shoW running-confi interface serial 0 IP address 10.1.1.1 router eigrp 11 network 10

RTR A#show Interface IP address

.0.0.0

running-serial 0 10.1.1.2

router eigrp 1 network 10 .0.0.0

255

conf

255

g

255

ig

255

255

.255

0

0

Figure 3 (3 marks)

ii) Briefly explain DUAL concept. (2 marks)

iii) Below is an opinion of David "Davis CCIE, MCSE+I, SCSA":

"While there is often a "right tool for the job," all routing protocols have their strengths and weaknesses, and I don't believe that there is a clear-cut best routing protocol that is the right tool for every network."

Do you agree with his view? Please support your answer with TWO (2) strengths and TWO (2) weaknesses of any two routing protocols and give ONE (1) example of scenario for each routing protocol as guidance on when it makes sense to use one or the other.

(6 marks)

QUESTION 2

a) State FOUR (4) techniques how distance vector routing protocols prevent routing loops. (4 marks)

b) RIPv2 and EIGRP is a type of distance vector routing protocol. Explain THREE (3) features of each type.

(6 marks)



c) State the command necessary in both version of RIP (RIPvl and RIPv2) to propagate a static default route.

(2 marks)

d) RIPvl network are automatically summarized across major network boundaries. Describe in detail the implication of automatic summarization with the help of Figure 4.

(8 marks)

Figure 4

QUESTION 3

a) Show how to protect a router:

i) from being viewed and configured by unauthorized users, ii) from being accessed remotely, iii) console port.

(6 marks)

b) Briefly explain the differences between static and dynamic routing in terms of:

i) configuration complexity. ii) scaling. iii) security. iv) resources usage.

(4 marks)



c) You were given the network address 192.168.1.0/24 to subnet and provide the IP addressing for a network. VLSM will be used so that the addressing requirements can be met using the 192.168.1.0/24 network. The network has the following addressing requirements:

LAN 1:28 nodes LAN 2: 22 nodes LAN 3: 30 nodes LAN 4: 12 nodes LAN 5: 8 nodes

(Note: It is not necessary to supply an address for the WAN connection because the Internet service provider supplies it.)

(6 marks)

d) State TWO (2) advantages of VLSM. (2 marks)

QUESTION 4

a) A new engineer is seeking for some advices from you. The company he is working with is planning to use OSPF for its network. Explain to him THREE (3) criteria that he is supposed to consider in making the decision.

(6 marks)

b) Explain why fast convergence of a network is crucial. (2 marks)

c) Differentiate between the three updates below :

i) Bounded update ii) Triggered update iii) Partial update

(3 marks)

d) One of the challenges presented by multi-access network is extensive LSA flooding. What would be the effect of extensive LSA flooding? Explain in detail how OSPF solve this issue.

(6 marks)

END OF QUESTION PAPER


ITT562 Routing Protocols And Concepts JUNE 2012.

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