Examen Corrigé En Réseaux Informatiques QCM

Examen Corrigé En Réseaux Informatiques QCM

Exercice 1 : (10 pts) - Choisir la bonne réponse - QCM -(2 pts pour chaque réponse)

Q1 : Quelle partie d’un réseau fournit des applications et des données aux ordinateurs hôtes
       

a)    Serveur  

b)    Concentrateur

c)    Routeur

d)    Pont

   

Q2 : A quoi sert une carte réseau ?
         

a)    Établie, gère et ferme les sessions entre des applications, et gère l’échange de données entre les entités de la couche présentation.

b)    Donne à l’hôte accès au média.

c)    Fournit des services aux processus d’applications

        

Q3 : Que connectent les routeurs ?
            

a)    Les ponts et les répéteurs

b)    Les ponts et les concentrateurs

c)    Deux réseaux ou plus

d)    Les concentrateurs et les nœuds

         

Q4 : A quoi sert un répéteur ?
        

a)    Connecter un réseau local à un réseau long distance

b)    Amplifier et resynchroniser les signaux réseau

c)    Enregistrer des pages Web et les répéter pour d’autres utilisateurs

d)    Transmettre les signaux horaires entre des unités réseau 

         

Q5 : Pour créer un réseau local simple de quatre ordinateurs, vous utiliseriez un(e) ______________ pour les raccorder.
           

a)    Câble d’interconnexion

b)    Ligne série

c)    Concentrateur

d)    Routeur

        

Q6 : Si quatre hôtes sont connectés à un concentrateur, puis à Internet, combien faut-il d’adresses IP pour ces cinq unités ?

        

a)    Un

b)    Deux

c)    Quatre

d)    Cinq

   

   

Q7 : Les unités d’interconnexions de réseaux sont utilisés pour relier des ?

           

a)    Réseaux locaux à d’autres réseaux locaux

b)    Réseaux locaux à des réseaux longue distance

c)    Réseau longue distance à d’autres réseaux longue distance

d)    Toutes ces réponses 

             

Q8 : Identifiez un avantage de l’utilisation de la fibre optique dans les réseaux.

       

a)    Peu coûteux

b)    Facile à installer

c)    Insensible aux interférences électromagnétiques  

d)    Disponible avec ou sans blindage extérieur

          

Q9 : Quel énoncé décrit le mieux la topologie de bus ?

       

a)    Tous les nœuds directement connectés à un point central tel qu’un concentrateur.

b)    Tous les nœuds sont directement connectés à une liaison physique.

c)    Tous les nœuds sont connectés à exactement deux autres nœuds. 

         

Q10 : Quelle définition parmi les suivantes décrit le mieux une topologie en étoile ?

        

a)    Topologie de réseau local selon laquelle un nœud central est connecté par câblage à d’autres nœuds qui en rayonnent.

b)    Topologies de réseau local selon laquelle les transmissions de stations réseau se propagent sur la longueur d’un câble coaxial unique.

c)    Topologie de réseau local qui utilise un nœud de circuit duquel partent les branches vers d’autres nœuds.

d)    Topologie de réseau local

      Partie Pratique : (20 pts) 
            

Exercice 1 : (10 pts)  

  

1) A  quoi  correspond  ce  schéma ?  Expliquez  le  mode  de  fonctionnement.

  

                    

2) Remplir le tableau suivant : (6 pts)

Adresse IP	Classe	Identificateur de Réseau	Identificateur d’hôte	Masque de sous réseau par défaut
12.3.2.1
220.30.2.5
56.9.6.4

3) Donner une commande pour tester la connexion entre deux ordinateurs. (2 pts)
   

4) Donner une commande pour afficher la configuration réseau d’un ordinateur. (2 pts)

                 

-------------------------------------------------------------------------------------------------

La Correction de l'examen

How to Save QuickTime Files or Movies from Within your Web Browser

Many web pages prevent you from saving QuickTime movies to your hard drive. Here are some hints to get you started.

Many web pages now exist for viewing QuickTime movies. You enjoy viewing and watching the movies; however, you cannot find out how to download them directly to your hard drive.
Based on the skill level of the web designer, it is possible to prevent users from directly downloading the movies’ files. Fortunately, however, most web designers do not go to such trouble. With a few simple hints, you have a good chance of directly downloading it.
Methods:
1. Right-click and Save Target As
If there is a direct link on the web page to the movie file, then it is very easy to download.
– Right click on the direct link to the movie file (*.mov).
– Select Save Target As.
– Name it and save it.
2. Find the link hidden in the source
Most web designers do not give a direct link; however, you can still find the link in the source code.
– Navigate to the page on which the movie is playing.
– Click View menu.
– Click Source.
– Notepad is open; click Edit menu.
– Select Find.
– In the text box type the following: .mov andmake sure you include the period.
– Typically the end of the url will be highlighted. The URL will like this, for example:
embed src= "http://www.blahblahblah.org/movies/hah_faptastic1.mov" border="0" bgcolor="#212121" controller="true" target="myself" pluginspage="http://www.apple.com/quicktime/download/" loop="FALSE" autoplay="true" height="262" width="320">
– Highlight and copy the URL part of the following:
http://www.blahblahblah.org/1/graphics/movies/hah_faptastic1.mov
– Paste this URL into your browser address bar, and click GO.
– When the film has completely loaded, click the File menu in your browser.
– Select Save As.
– Name and save your movie file.
Unfortunately, these two common methods will not work for all web applications. Many companies that developed highly complex methods for hiding the source quicktime files to prevent easy downloading.

Refer to the exhibit. A network technician enters the static route in R1 needed to reach network 10.1.1.0/24. A ping from R1 to Host B fails. The technician begins testing the network and has the following results

Refer to the exhibit. A network technician enters the static route in R1 needed to reach network 10.1.1.0/24. A ping from R1 to Host B fails. The technician begins testing the network and has the following results:

Refer to the exhibit. A network technician enters the static route in R1 needed to reach network 10.1.1.0/24. A ping from R1 to Host B fails. The technician begins testing the network and has the following results:
1. pings from R1 to the S0/0/0 interface on R2….successful
2. pings from R1 to the Fa0/0 interface on R2….successful
3. pings from Host B to hosts on the 10.1.1.0/24 network….successful
4. pings from Host B to the Fa0/0 interface on R2….successful
5. pings from R2 to Host B….successful

Read more »

Refer to the exhibit. What subnet mask will be applied by router B when it receives a RIPv1 update for the network 172.16.1.0?

none
8
16
24

Refer to the exhibit. A network administrator needs to create two subnetworks from 10.0.0.0/8 for a router running RIPv2. The Admin subnet requires 120 hosts and the Sales subnet requires 58 hosts. The network administrator assigned 10.0.1.128/25 to the Admin subnet. The Sales subnet is given 10.0.1.192/26. What will be the result of this addressing scheme?

Refer to the exhibit. A network administrator needs to create two subnetworks from 10.0.0.0/8 for a router running RIPv2. The Admin subnet requires 120 hosts and the Sales subnet requires 58 hosts. The network administrator assigned 10.0.1.128/25 to the Admin subnet. The Sales subnet is given 10.0.1.192/26. What will be the result of this addressing scheme?

Because RIPv2 does not support VLSM, the subnet masks will not be allowed.
The subnets will not have enough host addresses for the given network requirements.
The subnets overlap and will be rejected by the router.
The router will support the addressing scheme.

An additional subnet is required for a new Ethernet link between Router1 and Router2 as shown in the diagram. Which of the following subnet addresses can be configured in this network to provide a maximum of 14 useable addresses for this link while wasting the fewest addresses?

An additional subnet is required for a new Ethernet link between Router1 and Router2 as shown in the diagram. Which of the following subnet addresses can be configured in this network to provide a maximum of 14 useable addresses for this link while wasting the fewest addresses?

192.1.1.16/26
192.1.1.96/28
192.1.1.160/28
192.1.1.196/27
192.1.1.224/28
192.1.1.240/28

Refer to the exhibit. The number of required host addresses for each subnet in a network is listed in the exhibit. This number includes the host address requirements for all router ports and hosts on that subnet. After all device and router port address assignments are determined, what will be the total number of unused host addresses available?

Refer to the exhibit. The number of required host addresses for each subnet in a network is listed in the exhibit. This number includes the host address requirements for all router ports and hosts on that subnet. After all device and router port address assignments are determined, what will be the total number of unused host addresses available?

6
14
29
34
40
62

Refer to the exhibit. What subnet mask will be applied if Router A sends a RIPv1 update for the network 172.16.1.0 to Router B?

Refer to the exhibit. What subnet mask will be applied if Router A sends a RIPv1 update for the network 172.16.1.0 to Router B?

Read more »

Refer to the exhibit. In the network that is shown, the router interfaces are assigned the first address in each subnet. Which IP address would be usable for a host on one of the LANs in this network?

Refer to the exhibit. In the network that is shown, the router interfaces are assigned the first address in each subnet. Which IP address would be usable for a host on one of the LANs in this network?

Read more »

A Class C address has been assigned for use in the network shown in the graphic. Using VLSM, which bit mask should be used to provide for the number of host addresses required on Router A, while wasting the fewest addresses?

A Class C address has been assigned for use in the network shown in the graphic. Using VLSM, which bit mask should be used to provide for the number of host addresses required on Router A, while wasting the fewest addresses?

/31
/30
/29
/28
/27
/26

Refer to the exhibit. A network engineer is summarizing the two groups of routes on router R1 shown in the exhibit. Which summarization will work for all the subnets?

192.168.0.0/23
192.168.0.0/22
192.168.0.0/21
192.168.0.0/20

Read more »

Refer to the exhibit. A network technician enters the static route in R1 needed to reach network 10.1.1.0/24. A ping from the S0/0/0 interface on R1 to host B fails. The technician begins testing the network and has the following results:

1. pings from R1 to the S0/0/0 interface on R2….successful
2. pings from R1 to the Fa0/0 interface on R2….successful
3. pings from host B to hosts on the 10.1.1.0/24 network….successful
4. pings from host B to the Fa0/0 interface on R2….successful
5. pings from R2 to host B….successful.

What is the likely cause of the failure of the ping from R1 to host B?

The default gateway on host B is not correctly set.
There are no routes back to networks connected to R1 from R2.
There is a Layer 2 problem between R2 and host B.
Host B has a defective Ethernet card.

A network administrator is tasked with dividing up a class C network among the QA, Sales, and Administration departments. The QA department is made up of 10 people, the Sales is made up of 28 people, and the Administration has 6. Which two subnets masks adequately address the QA and Sales departments? (Choose two.)

255.255.255.252 for QA
255.255.255.224 for Sales
255.255.255.240 for QA
255.255.255.248 for QA
255.255.255.0 for Sales

Which of the following problems does VLSM help to alleviate?

the shortage of IP addresses
the difficulty of assigning static IP addresses to hosts in large enterprises
the complexity of implementing advanced routing protocols such as OSPF and EIGRP
the shortage of network administrators qualified in the use of RIP v1 and IGRP

Read more »

Which three interior routing protocols support VLSM? (Choose three.)

OSPF
RIP v1
RIP v2
EIGRP
BGP
STP

Read more »

What does VLSM allow a network administrator to do?

utilize one subnet mask throughout an autonomous system
utilize multiple subnet masks in the same IP address space
utilize IGRP as the routing protocol in an entire autonomous system
utilize multiple routing protocols within an autonomous system

Read more »

Refer to the exhibit. The network administrator wants to create a subnet for the point-to-point connection between the two routers. Which subnetwork mask would provide enough addresses for the point-to-point link with the least number of wasted addresses?

Refer to the exhibit. The network administrator wants to create a subnet for the point-to-point connection between the two routers. Which subnetwork mask would provide enough addresses for the point-to-point link with the least number of wasted addresses?

Read more »

In the network shown in the graphic, three bits were borrowed from the host portion of a Class C address. How many valid host addresses will be unused on the three point-to-point links combined if VLSM is not used?

In the network shown in the graphic, three bits were borrowed from the host portion of a Class C address. How many valid host addresses will be unused on the three point-to-point links combined if VLSM is not used?

Read more »

Refer to the exhibit. Which address is a broadcast address for one of the subnets that are shown in the exhibit?

Refer to the exhibit. Which address is a broadcast address for one of the subnets that are shown in the exhibit?

192.168.4.3/29
192.168.4.15/29
192.168.4.65/26
192.168.4.255/24

What two advantages does CIDR provide to a network? (Choose two.)

reduced routing table size
dynamic address assignment
automatic route redistribution
reduced routing update traffic
automatic summarization at classful boundaries

Read more »

Which of the following are contained in the routing updates of classless routing protocols? (Choose two.)

32-bit address
next hop router interface
subnet mask
unicast host address
Layer 2 address

Read more »

ccna exploration 1 chapter 5 exam answers

ccna exploration 1 chapter 5 exam answers

What is a component of a routing table entry?

• the MAC address of the interface of the router
• the destination Layer 4 port number
• the destination host address
• the next-hop address

 

Which portion of the network layer address does a router use to forward packets?

• host portion
• broadcast address
• network portion
• gateway address

What information is added during encapsulation at OSI Layer 3?

• source and destination MAC
• source and destination application protocol
• source and destination port number
• source and destination IP address

 

What statement describes the purpose of a default route?

• A host uses a default route to transfer data to another host on the same network segment.
• A host uses a default route to forward data to the local switch as the next hop to all destinations.
• A host uses a default route to identify the Layer 2 address of an end device on the local network.
• A host uses a default route to transfer data to a host outside the local network when no other route to the destination exists.

In a connectionless system, which of the following is correct?

• The destination is contacted before a packet is sent.
• The destination is not contacted before a packet is sent.
• The destination sends an acknowledgement to the source that indicates the packet was received.
• The destination sends an acknowledgement to the source that requests the next packet to be sent.

Refer to the exhibit. Using the network in the exhibit, what would be the default gateway address for host A in the 192.133.219.0 network?

• 192.135.250.1
• 192.31.7.1
• 192.133.219.0
• 192.133.219.1

If the default gateway is configured incorrectly on the host, what is the impact on communications?

• The host is unable to communicate on the local network.
• The host can communicate with other hosts on the local network, but is unable to communicate with hosts on remote networks.
• The host can communicate with other hosts on remote networks, but is unable to communicate with hosts on the local network.
• There is no impact on communications.

What is the purpose of a default gateway?

• physically connects a computer to a network
• provides a permanent address to a computer
• identifies the network to which a computer is connected
• identifies the logical address of a networked computer and uniquely identifies it to the rest of the network
• identifies the device that allows local network computers to communicate with devices on other networks 

What type of routing uses information that is manually entered into the routing table?

• dynamic
• interior
• static
• standard

When the destination network is not listed in the routing table of a Cisco router, what are two possible actions that the router might take? (Choose two.)

• The router sends an ARP request to determine the required next hop address.
• The router discards the packet.
• The router forwards the packet toward the next hop indicated in the ARP table.
• The router forwards the packet to the interface indicated by the source address.
• The router forwards the packet out the interface indicated by the default route entry.

In an IPv4 environment, what information is used by the router to forward data packets from one interface of a router to another?

• destination network address
• source network address
• source MAC address
• well known port destination address

What are the key factors to consider when grouping hosts into a common network? (Choose three.)

• gateways
• purpose
• physical addressing
• software version
• geographic location
• ownership

Which intermediary devices could be used to implement security between networks? (Choose two.)

• router
• hub
• switch
• firewall
• access point
• bridge

What are three common problems with a large network? (Choose three.)

• too few broadcasts
• performance degradation
• security issues
• limited management responsibility
• host identification
• protocol compatibility

Refer to the exhibit. All devices shown in the exhibit have factory default settings. How many broadcast domains are represented in the topology that is shown?

• 3
• 4
• 5
• 7
• 8
• 11

 

Refer to the exhibit. The network in the exhibit is fully operational. What two statements correctly describe the routing for the topology that is shown? (Choose two.)

• 192.168.0.2 is the next-hop address that is used by R3 to route a packet from the 10.0.0.0 network to the 172.16.0.0 network.
• 10.0.0.1 is the next-hop address that is used by R1 to route a packet from the 192.168.12.0 network to the 10.0.0.0 network.
• 192.168.0.1 is the next-hop address that is used by R1 to route a packet from the 192.168.12.0 network to the 172.16.0.0 network.
• 172.16.0.1 is the next-hop address that is used by R3 to route a packet from the 10.0.0.0 to the 172.16.0.0 network.
• 192.168.0.1 is the next-hop address that is used by R2 to route a packet from the 172.16.0.0 network to the 192.168.12.0 network.
• 192.168.0.2 is the next-hop address that is used by R2 to route a packet from the 172.16.0.0 network to the 192.168.12.0 network.

 

Which three statements are true about routes and their use? (Choose three.)

• If no route to the destination network is found, the packet is returned to the previous router.
• If the destination network is directly connected, the router forwards the packet to the destination host.
• If multiple network entries exist for the destination network, the most general route is used to forward the packet.
• If no route exists for the destination network and a default route is present, the packet is forwarded to the next-hop router.
• If the originating host has a default gateway configured, the packet for a remote network can be forwarded using that route.
• If a host does not have a route manually configured for the destination network, the host will drop the packet.

Refer to the exhibit. A network administrator is troubleshooting a connectivity problem and needs to determine the address that is used to forward network packets out the network. Using the netstat -r command, the administrator would identify which address as the address to which all hosts send packets that are destined for an outside network?

• 10.10.10.26
• 127.0.0.1
• 10.10.10.6
• 10.10.10.1
• 224.0.0.0

Refer to the exhibit. A network administrator notices that there are too many broadcasts on the network. What two steps can the network administrator take to resolve this problem? (Choose two.)

• Replace S2 with a router.
• Place all servers on S1.
• Disable TCP/IP broadcasts.
• Subnet the 192.168.0.0 /24 network.
• Disable all unused interfaces on the switches.

Which IP packet field will prevent endless loops?

• type-of-service
• identification
• flags
• time-to-live
• header checksum

What two characteristics are commonly associated with dynamic routing protocols? (Choose two.)

• require no device configuration
• provide routers with up-to-date routing tables
• require less processing power than static routes require
• consume bandwidth to exchange route information
• prevent manual configuration and maintenance of the routing table