ICND1 – Basic Questions 2

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Question 1

[am4show have=’p2;’]Which two options will help to solve the problem of a network that is suffering a broadcast storm? (Choose two)

A. a bridge
B. a router
C. a hub
D. a Layer 3 switch
E. an access point

 

Answer: B D[/am4show]

Explanation

Only a router or a Layer 3 switch can mitigate a broadcast storm because they separate broadcast domains -> B and D are correct.

Question 2

[am4show have=’p2;’]Refer to the exhibit. A network has been planned as shown. Which three statements accurately describe the areas and devices in the network plan? (Choose three)

A. Network Device A is a switch.
B. Network Device B is a switch.
C. Network Device A is a hub.
D. Network Device B is a hub.
E. Area 1 contains a Layer 2 device.
F. Area 2 contains a Layer 2 device.

 

Answer: A D E[/am4show]

Explanation

AREA 1 has “multiple collision domains” so Network Device A must be a device operating in Layer 2 or above (a router or switch) -> A & E are correct.

AREA 2 only has “single collision domain” so Network Device B must be a device operating in Layer 1 (a hub or repeater) -> D is correct.

Question 3

[am4show have=’p2;’]Refer to the exhibit. If the resume command is entered after the sequence that is shown in the exhibit, which router prompt will be displayed?

A. Router1>
B. Router1#
C. Router2>
D. Router2#

 

Answer: C[/am4show]

Explanation

The “Ctrl-Shift-6” and “x” is used to suspend the telnet session. In this case, the telnet session from Router1 to Router2 will be suspended.

If we enter the keyword “resume”, Router1 will try to resume the telnet session to Router2 (you will see the line [Resuming connection 1 to 192.168.9.2 … ]) and we will get back the Router2> prompt.

Question 4

[am4show have=’p2;’]Refer to the exhibit. All devices attached to the network are shown. How many collision domains are present in this network?

A. 2
B. 3
C. 6
D. 9
E. 15

 

Answer: E[/am4show]

Explanation

In the topology above only routers and switches are used so for each link we have one collision domains. In the picture below each pink ellipse represents for one collision domain.

Question 5

[am4show have=’p2;’]Which network topology allows all traffic to flow through a central hub?

A. bus
B. star
C. mesh
D. ring

 

Answer: B[/am4show]

Explanation

Star topology is the most popular topology for the network which allows all traffic to flow through a central device.

Question 6

[am4show have=’p2;’]On which type of device is every port in the same collision domain?

A. a router
B. a Layer 2 switch
C. a hub

 

Answer: C[/am4show]

Question 7

[am4show have=’p2;’]Which feature allows a device to use a switch port that is configured for half-duplex to access the network?

A. CSMA/CD
B. IGMP
C. port security
D. split horizon

 

Answer: A[/am4show]

Explanation

Carrier Sense Multiple Access with Collision Detection (CSMA/CD) is the LAN access method used in Ethernet. When a device wants to gain access to the network, it checks to see if the network is free. If the network is not free, the device waits a random amount of time before retrying. If the network is free and two devices access the line at exactly the same time, their signals collide. When the collision is detected, they both back off and wait a random amount of time before retrying.

CSMA/CD is used with devices operating in half-duplex mode only. CSMA/CD helps devices connecting to half-duplex switch ports operate correctly.

Question 8

[am4show have=’p2;’]Which MTU size can cause a baby giant error?

A. 1500
B. 9216
C. 1600
D. 1518

 

Answer: D[/am4show]

Explanation

Ethernet frame size refers to the whole Ethernet frame, including the header and the trailer while MTU size refers only to Ethernet payload. Baby giant frames refer to Ethernet frame size up to 1600 bytes, and jumbo frame refers to Ethernet frame size up to 9216 bytes (according to this link: http://www.cisco.com/c/en/us/support/docs/switches/catalyst-4000-series-switches/29805-175.html)

For example, standard Ethernet frame MTU is 1500 bytes. This does not include the Ethernet header and Cyclic Redundancy Check (CRC) trailer, which is 18 bytes in length, to make the total Ethernet frame size of 1518.

So according to strict definition, MTU size of 1600 cannot be classified as baby giant frames as the whole Ethernet frames will surely larger than 1600 -> Answer C is not correct.

Answer D is a better choice as the MTU is 1518, so the whole Ethernet frame would be 1536 (1518 + 18 Ethernet header and CRC trailer). This satisfies the requirement of baby giant frames “Baby giant frames refer to Ethernet frame size up to 1600 bytes”.

Question 9

[am4show have=’p2;’]What happens when the cable is too long?

A. Baby Giant
B. Late collision
C. Duplex mismatch
D. No connection

 

Answer: B[/am4show]

Question 10

[am4show have=’p2;’]To what type of port would a cable with a DB-60 connector attach?

A. Serial port
B. Console port
C. Ethernet port
D. Fibre optic port

 

Answer: A[/am4show]

Question 11

[am4show have=’p2;’]Refer to the exhibit:

What kind of cable should be used to make each connection that is identified by the numbers shown?

A.
1 – Ethernet straight-through cable
2 – Ethernet crossover cable
3 – Serial cable
4 – Ethernet straight-through cable
B.
1 – Ethernet rollover cable
2 – Ethernet crossover cable
3 – Serial cable
4 – Null modem cable
C.
1 – Ethernet straight-through cable
2 – Ethernet crossover cable
3 – Serial cable
4 – Rollover cable
D.
1 – Ethernet crossover cable
2 – Ethernet straight-through cable
3 – Fiber Optic cable
4 – Rollover cable
E.
1 – Ethernet straight-through cable
2 – Ethernet straight-through cable
3 – Serial cable
4 – Rollover cable

 

Answer: E[/am4show]

Explanation

To remember which type of cable you should use, follow these tips:

– To connect two serial interfaces of 2 routers we use serial cable
– To specify when we use crossover cable or straight-through cable, we should remember:
Group 1: Router, Host, Server
Group 2: Hub, Switch
One device in group 1 + One device in group 2: use straight-through cable
Two devices in the same group: use crossover cable

For example: we use straight-through cable to connect switch to router, switch to host, hub to host, hub to server… and we use crossover cable to connect switch to switch, switch to hub, router to router, host to host… )

Notice in this question, connecting to the Frame Relay means connecting to another router. Also we must use serial cable (or Fiber Optic cable) because the distance to the Frame Relay is far so we can’t use Ethernet cables.

Rollover cable can be used to connect a computer terminal to a network router’s console port. This is often used when we turn on the router for the first time.

Question 12

[am4show have=’p2;’]Refer to the exhibit. How many collision domains are shown?

A. one
B. two
C. three
D. four
E. six
F. twelve

 

Answer: B[/am4show]

Question 13

[am4show have=’p2;’]Refer to the exhibit. Pierre has just installed the mail server and Switch2. For security reasons UDP packets are not permitted outbound on the Fa0/1 router interface. Pierre is now at his workstation testing the new installation and is not able to establish SMTP communication to the mail server.

What is the most likely cause for lack of communication between Pierre’s workstation and the mail server?

A. The crossover cable should be a straight-through cable.
B. UDP is blocked coming out of the Fa0/1 interface on the router.
C. The server should be directly connected to the router.
D. The IP addresses are all on the same network. No router is required.

 

Answer: A[/am4show]

Question 14

[am4show have=’p2;’]Refer to the exhibits labeled A through E. All devices are to be connected over Ethernet. Which three device-to-device configurations are likely to require the use of a crossover connection? (Choose three.)

A. exhibit A
B. exhibit B
C. exhibit C
D. exhibit D
E. exhibit E

 

Answer: A D E[/am4show]

Question 15

[am4show have=’p2;’]Refer to the exhibit. All devices attached to the network are shown. Which number of collision domains are present in this network?

A. 9
B. 3
C. 6
D. 2
E. 15

 

Answer: E[/am4show]

Explanation

Both switch and router separate collision domains. In other words, each port of the switch and router creates one collision domain so we have 15 collision domains in this topology.