Ethernet over MPLS

Back>

Fiber optics allows the ethernet cable to connect nodes tens of miles apart. It is long enough to cover the distance from the customer premise equipment (CPE) to service provider's point of presence (POP), it is even long enough to cover the distance from one city to another.

Internet service providers (ISPs) quickly turn this new technology into profit by offering ethernet based WAN services.

Your little-rock-city SOHO LAN is connect to the CPE router in the little-rock-city commercial center building with an ethernet cable. The CPE router then connects to a special ethernet switch located in the local ISP central office (CO) with an ethernet cable (fiber optics). This central office provides a point of presence (POP). Behind the ethernet switch, ISP can uses any WAN technology to connect their devices internally. In another city,  say big-river-city, the ISP's central office provides another POP, where another special ethernet switch connects to your CPE router located in -- well -- big-river-city commercial center building with a fiber optic ethernet cable, this CPE router then connects to you big-river-city SOHO LAN with an ethernet cable.

The internal WAN connection can vary from ISP to ISP. However, from customer's perspective: a point-to-point connection is established between two remote CPEs connected with a (long, virtual) ethernet link.

Ethernet over Multiprotocol Label Switching (EoMPLS) is one of those WAN technologies that can provide that "long, virtual ethernet link".

Recall the routing process in HDLC WAN.When an IP packet from source PC needs to travel across WAN to reach destination PC, the IP packet has to be de-encapsulated and re-encapsulated between Ethernet frame and HDLC frame.

EoMPLS uses ethernet for both layer 1 and layer 2 functions, routing over an EoMPLS WAN uses the same Ethernet protocols as LAN. Instead of switching between Ethernet and HDLC, EoMPLs use the Ethernet protocol all the time.

IP packet travel LAN and EoMPLS

At the beginning, the sending node encapsulates the IP packet in an Ethernet frame with the destination MAC address of the gateway router. This Ethernet frame travels across the LAN and reaches the gateway router. At the gateway router, the Ethernet frame is de-encapsulated to extract the IP packet. This IP packet is then encapsulated in another ethernet frame, this time, the destination MAC address is the MAC address of the receiving gateway router. The ethernet frame is then forwarded to the EoMPLS WAN network. The Ethernet frame travels across EoMPLS WAN and reaches other side of the point to point link, which is the receiving LAN's gateway router. The Ethernet frame is de-encapsulated to extract the IP packet. This IP packet is then encapsulated in an Ethernet frame with the destination MAC address as the receiving node. Finally the Ethernet frame travels across the LAN and reaches the receiving node. The return journey follow the same ethernet frame header/trailer changing process.

ISP, POP, NSP, NAP, MAE, IXP

Back>

The following diagram is an overall architecture of internet.

You home PC connects to a home LAN, your home LAN then connects to a tier 3 ISP, the tier 3 ISP have access to a NSP's network infrastructure (fibers, routers etc.) via a POP. These NSPs have peer to peer connections via NAP or IXP, so that the internet made of inter-connected NSPs span the whole globe.

ISP and NAP

• Local Loop also called "last mile", is a copper or fiber cable that connects the demarc to the closest switching office, called a central office. In the diagram, the local loop is a T1 line.
• Internet Service Provider (ISP), An Internet Service Provider (ISP) is a company that provides Internet access. The most common ISP is the provider who delivers Internet to your home or business for a fee. 
• Central office (CO) also called point of presence (POP), connects the customers to the provider's switching network. It is the entry point to the WAN cloud and the exit point from the WAN for called devices. The tier 3 Internet service provider (ISP) often has multiple point-of-presence in major cities, which are connected together by the leased lines from NSP.
• Network Service Providers (NSP) A network service provider (NSP) is a company that owns, operates and sells access to internet backbone infrastructure and services. They often sell network to tier 3 ISPs, or act as ISP by themselves. NSPs build and maintain the fiber optic cable and core routers. Some of the large NSPs are UUNet, CerfNet, IBM, BBN Planet, SprintNet, PSINet, as well as others. These networks peer with each other to exchange packet traffic via NAP. 
• Network Access Points (NAP) is a public network exchange facility where Internet Service Providers (ISPs) can connect with one another in peering arrangements. The NAPs are a key component of the Internet backbone because the connections within them determine how traffic is routed. They are also the points of most Internet congestion.
• Metropolitan Area Exchanges (MAEs). MAEs serve the same purpose as the NAPs but are privately owned. NAPs were the original Internet interconnect points. Both NAPs and MAEs are referred to as Internet Exchange Points (IXs).
• Tier 1 ISP, Tier 2 ISP and Tier 3 ISP, ISPs are categorized by their size. Tier 3 are generally small ISPs who only purchase their connection to the Internet from NSP. Tier 1 are generally internet giant NSP who owns so much network infrastructure that they don’t need to purchase any connection from other ISPs. These major players “peer” with other to allow the traffic between their networks to flow back and forth. Tier 2 are providers who have some interconnection agreements, but who also purchase some connections. Largest Tier 1 Internet providers are the networks that provide the backbone of the Internet. These providers build infrastructure such as the Atlantic Internet sea cables. These infrastructures allow the data exchange between continent and countries. Examples are Hibernia Networks, Cogent Communications.

How to setup WAN at home

LAN and WAN are similar layer 1 and layer 2 technology. Small company usually use a leased line to connect the LANs in their branch offices cross a WAN.

Knowing the following 3 factors, you should be able to setup a WAN lab at home.

1. The leased line service conceptually acts as a full-duplex crossover Ethernet link between two routers. 
2. Another factor about WAN is you need a CSU/DSU device. A CSU/DSU is a digital signal processing device. The DSU portion is responsible for timing, and actually connects to the DTE router via its serial port. The CSU portion is responsible for terminating the service provider’s link, and handles transmitting and receiving data from the DCE switch over the WAN link.
3. The DCE cable has a female connector, while the DTE cable has a male connector. You can plug the DTE cable directly into the DCE cable, skipping the CSU/DSU device. As a result, the WAN link is conceptually two routers linked by a cross over cable.

Follow the following guidelines, you should be able to figure out how to setup the network:

• You need to get these equipment from your friends, cisco, ebay, craggiest, amazon etc: one DCE/DTE DB60 Crossover Cable, two cisco routers with WIC-2T interface.
• Now you can plug one side of the crossover cable into one cisco router's  DB-60 port. This router will acts as the service provider's DCE switch; you then plug the other end of the crossover cable into another cisco router's DB-60 port. This router will act as the organization's DTE router. 
• The only problem at this point is, you don't have DSU to provide timing. Don't worry, you can configure serial clocking using the "clock rate 128000" command on the router that act as the DCE switch. The rest of the configuration is the same as connecting two routers with serial connection.

R1(config-if) # interface S0/0/1

R1(config-if) # ip address 172.16.3.1 255.255.255.0

R1(config-if) # clock rate 128000

R1(config-if) # no shutdown

Configuring Cisco ASA/PIX 7.x for SSH

If you have already configured SSH it does not seem to be working when tested with an SSH Client (like PuTTY), then we recommend using the "diag SSH" command in a telnet or console session to see what the problem is.
If configuring from scratch, then our first task is to generate an RSA public/private key pair to use to securely transfer the session key from the server to the client. The hostname and domain-name must be set before the ASA/PIX will allow you to generate the key pair.

To begin in configuration login to the Cisco ASA/PIX using the console or telnet. then enter enable mode and then configuration mode:

Percival> enable
Password: *******
Percival# configure terminal

1. Assign a hostname and domain name to the ASA/PIX. This is required to generate the RSA key set.

pixfirewall(config)# hostname percival

percival(config)# domain-name cisco.com

2. Generate an RSA Key pair and save the keys to Flash memory.

percival(config)# crypto key generate rsa

WARNING: You have a RSA keypair already defined named .
Do you really want to replace them? [yes/no]: y
Keypair generation process begin. Please wait...

3. View your newly created RSA Public Key.

percival(config)# show crypto key mypubkey rsa

Key pair was generated at: 21:26:02 GMT/BDT Aug 19 2008

Key name:

Usage: General Purpose Key

Modulus Size (bits): 1024

Key Data:

30819f30 0d06092a 864886f7 0d010101 05000381 8d003081 89028181 00a85845

15ad4990 5302cdc5 29ecedff 9fd70562 cf1db5b5 04baf537 1ff646d4 e090d5ca

58128028 b362ce22 0c540a6a 76c5c18f 3de5fa20 b94c66c9 e7523a97 4a899317

0209c7d5 7b754da4 76f7e359 58c15570 da8c765d 6a06939e acc64c7a 3a684c7e

7a586c77 3efc4139 8e14e330 20911a6f 003242b7 b952f4a9 7687571a 11020301 0001

Key pair was generated at: 18:12:37 GMT/BDT Aug 19 2008

Key name: .server

Usage: Encryption Key

Modulus Size (bits): 640

Key Data:

306c300d 06092a86 4886f70d 01010105 00035b00 30580251 00b41c50 fee794d7

109d198e 2ea1bd1f 24866fad 4623b081 afceb803 7b5889e2 908c343d 38c0dab6

44a02c35 61993036 863891ae fb89df47 6e0cbd2e 4a24227b 77ada29a 6e234604

63bcaf5a 50b627a7 cb020301 000123020301 0001

4. Specify what hosts are allowed to SSH to the ASA/PIX and set the SSH inactivity timeout. In this case, you will limit SSH access to a single inside host and kill sessions after one hour of inactivity.

percival(config)# ssh 192.168.111.7 255.255.255.255 inside

percival(config)# ssh timeout 60

5. Set the enable password and Telnet password. You will be required to enter the Telnet password to authenticate your SSH session**.

percival(config)# enable password hArd2Gue$$

percival(config)# passwd Ace$$D3n13d

To exit configuration mode press [CTRL]-Z and to save configuration to flash memory:

Percival # write memory

**Note: If you have previously configured a telnet password and enable password, you don't need to change them for SSH to work.

Routing Process Continued -- Behind the PING

ICND1 and ICND2 break down

In a previous post, we have examined host to host communication process, here we will examine routing process step by step. Understanding the routing process is critical to pass your CCENT and CCNA exam, and it is also the fundamental of networks, so let's make it crystal clear by looking at an example.

The modern Internet Ping command refers to a program was written by Mike Muuss in December, 1983. It sends a small packet of information containing an ICMP ECHO_REQUEST to a specified computer, which then sends an ECHO_REPLY packet in return. Let's exam what happens after a ping command is issued.

behind the ping

Refer to the exhibit. The LAN contains 2 hosts, 2 hubs and 2 routers. With subnetmask 255.255.255.240 or /27, router R4 and R5 divide the LAN into 3 subnets -- host A and R4's 192.168.10.33/27 interface belongs to 192.168.10.32 subnet; R4's 192.168.10.65/27 interface and R5's 192.168.10.66/27 interface belongs to 192.168.10.64 subnet; R5's 192.168.10.129/27 interface and host B belongs to 192.168.10.128 subnet.  Notice the layer 1 device hub have neither IP address nor ethernet address.

Now, host A pings host B, what happened exactly behind the magic "PING" command.

• Step 1, command "ping 192.168.10.134" is issued in the console at host A.


• ping program is envoked, which reads IP address 192.168.10.138 from user input, and hands it to Internet Control Message Protocol (ICMP).


• ICMP then creates an echo request payload.


• ICMP hands the payload to Internet Protocol (IP). IP then creates a packet with IP source address 192.168.10.34 and destination address 192.168.10.134. The Protocol field of the packet has value 0x01, which means ICMP.


• After the packet creation, IP determines whether the destination IP address is on the local network or a remote network. The subnet mask stored on Host A 255.255.255.240 is bitwise AND to host A's IP address 192.168.10.34 to determine that host A belongs to 192.168.10.32 subnet. With the same manner, IP determines that host B belongs to another subnet 192.168.10.128. 


• Since IP determines that this is a remote request, the packet needs to be sent to the default gateway so the packet can be routed to the remote network. The default gateway is stored in host A as 192.168.10.33 (either statically configured by the user or dynamically configured by DHCP).


• Because hosts only communicate via hardware addresses on the local LAN, for this packet to be sent to the default gateway, the hardware address of the default gateway (router's interface with IP address 192.168.10.33) must be known. 


• The ARP cache of the host is checked to see if the IP address of the default gateway has already been resolved to hardware address. If it has, the packet is then handed to the Data Link layer with the hardware destination address. Otherwise, an ARP broadcast (to IP address 192.168.10.63) is sent out onto the broadcast domain (subnet 192.168.10.32) to search for the hardware address of 192.168.10.33. The router responds to the request with hardware address of ethernet interface 192.168.10.33, and Host A caches this address.


• IP hands the packet down to Data Link layer for framing. The Data Link layer frames the packet of information and includes the following in the header: the destination hardware address 9999.DADC.1234, the source hardware address BBBB.3333.5677, the Ether-Type field with 0x0800 (IP) in it, and the FCS field with the CRC result.


• The frame is now handed down to the physical layer to be sent out over the network medium one bit at a time.


• The router R4's Ethernet interface with MAC address 9999.DADC.1234 receives the bits and builds a frame. The CRC is run, and FCS field is checked to make sure the answers match.


• Once the CRC is found to be okay, the hardware destination address is checked. Since the router's interface is a match, the packet is pulled from the frame and the Ether-Type field is checked to see what protocol at the Network layer the packet should be delivered to.


• The protocol is determined to be IP, so it gets the packet. IP runs a CRC check on the IP header first and then checks the destination IP address. The destination address is 192.168.10.134, which doesn't match any of the router R4's interfaces. Therefore, the routing table is checked to see whether it has a route to 192.168.10.134. If there's no entry found for 192.168.10.134, the packet will be discarded. If there's an entry found for 192.168.10.134, (For example, command "show ip route" reveals an entry such as "S    192.168.10.134/24 [1/0] via 192.168.10.66") the packet is ready to be sent out from interface 192.168.10.65, which directly connects to the next hop 192.168.10.66.


• The router checks the ARP cache to determine whether the hardware address for 192.168.10.66 has already been resolved. If it has, the packet is then handed to the Data Link layer with the hardware destination address. Otherwise, an ARP broadcast (to IP address 192.168.10.95) is sent out onto the broadcast domain (subnet 192.168.10.64) to search for the hardware address of 192.168.10.66. The router R5 responds to the request with hardware address of ethernet interface 192.168.10.66, and Router R4 caches this address.


• The hardware address and packet are handed to the Data Link layer. The Data Link layer builds a frame with the destination address (MAC address corresponding to 192.168.10.66, not shown in the exhibit) and source hardware address (MAC address corresponding to 192.168.10.65, not shown in the exhibit) and then puts IP in the Ether-Type field. A CRC is run on the frame and the result is placed in the FCS field.


• The frame is then handed to the Physical layer to be sent out onto the local network one bit at a time.


• The destination Router R5 receives the frame, runs a CRC, checks the destination hardware address, and looks in the Ether-Type field to find out whom to hand the packet to.


• The protocol is determined to be IP, so it gets the packet. IP runs a CRC check on the IP header first and then checks the destination IP address. The destination address is 192.168.10.134, which doesn't match any of the router R5's interfaces. Therefore, the routing table is checked to see whether it has a route to 192.168.10.134. If there's no entry found for 192.168.10.134, the packet will be discarded. But router R5 is directly connected with Host B, there should be an entry in the routing table like "C    192.168.10.134/24 is directly connected, FastEthernet0".  This means the packet is ready to be sent out from interface 192.168.10.129, which directly connects to the Host B 192.168.10.134. Notice hub don't have IP address, it is just a multi-port signal repeater.


• The router checks the ARP cache to determine whether the hardware address for 192.168.10.134 has already been resolved. If it has, the packet is then handed to the Data Link layer with the hardware destination address. Otherwise, an ARP broadcast is sent (to IP address 192.168.10.159) out onto the broadcast domain (subnet 192.168.10.128) to search for the hardware address of 192.168.10.134. The Host B responds to the request with hardware address DDDD.4444.1357, and Router R5 caches this address.


• The hardware address and packet are handed to the Data Link layer. The Data Link layer builds a frame with the destination address DDDD.4444.1357 and source hardware address 5555.AAAA.6666 and then puts IP in the Ether-Type field. A CRC is run on the frame and the result is placed in the FCS field.


• The frame is then handed to the Physical layer to be sent out onto the local network one bit at a time.


• The destination Host B receives the frame, runs a CRC, checks the destination hardware address, and looks in the Ether-Type field to find out whom to hand the packet to.


• IP is the designated receiver, and after the packet is handed to IP at the Network layer, it checks the protocol field for further direction. IP finds instructions to give the payload to ICMP, and ICMP determines the packet to be an ICMP echo request.


• ICMP creates an echo reply payload.


• ICMP hands the payload to Internet Protocol (IP). IP then creates a packet with IP source address 192.168.10.134 and destination address 192.168.10.34. The Protocol field of the packet has value 0x01, which means ICMP.


• After the packet creation, IP determines whether the destination IP address is on the local network or a remote network.


• Since IP determines that this is a remote request, the packet needs to be sent to the default gateway so the packet can be routed to the remote network. The default gateway is stored in host B as 192.168.10.129 (either statically configured by the user or dynamically configured by DHCP).


• The hardware address of 192.168.10.129 is found with ARP process, and the hardware address 5555.AAAA.6666 and packet are handed to the Data Link layer.


• The Data Link layer builds a frame with the destination hardware address 5555.AAAA.6666 and source hardware address DDDD.4444.1357 and then puts IP in the Ether-Type field. A CRC is run on the frame and the result is placed in the FCS field.


• The frame is then handed to the Physical layer to be sent out onto the local network one bit at a time.


• The destination router R5 receives the frame, runs a CRC, checks the destination hardware address, and looks in the Ether-Type field to find out whom to hand the packet to.


• IP is the designated receiver, and after the packet is handed to IP at the Network layer, IP runs a CRC check on the IP header first and then checks the destination IP address. The destination address is 192.168.10.34, which doesn't match any of the router R5's interfaces. Therefore, the routing table is checked to see whether it has a route to 192.168.10.34. If there's no entry found for 192.168.10.34, the packet will be discarded. If there's an entry found for 192.168.10.34, (For example, command "show ip route" reveals an entry such as "S    192.168.10.34/24 [1/0] via 192.168.10.65") the packet is ready to be sent out from interface 192.168.10.66, which directly connects to the next hop 192.168.10.65.


• The router checks the ARP cache to determine whether the hardware address for 192.168.10.65 has already been resolved. If it has, the packet is then handed to the Data Link layer with the hardware destination address. Otherwise, an ARP broadcast is sent out onto the network to search for the hardware address of 192.168.10.65. The router R4 responds to the request with hardware address of ethernet interface 192.168.10.65, and Router R5 caches this address.


• The hardware address and packet are handed to the Data Link layer. The Data Link layer builds a frame with the destination address (MAC address corresponding to 192.168.10.65, not shown in the exhibit) and source hardware address (MAC address corresponding to 192.168.10.66, not shown in the exhibit) and then puts IP in the Ether-Type field. A CRC is run on the frame and the result is placed in the FCS field.


• The frame is then handed to the Physical layer to be sent out onto the local network one bit at a time.


• The destination Router R4 receives the frame, runs a CRC, checks the destination hardware address, and looks in the Ether-Type field to find out whom to hand the packet to.


• The protocol is determined to be IP, so it gets the packet. IP runs a CRC check on the IP header first and then checks the destination IP address. The destination address is 192.168.10.34, which doesn't match any of the router R4's interfaces. Therefore, the routing table is checked to see whether it has a route to 192.168.10.34. If there's no entry found for 192.168.10.34, the packet will be discarded. But router R4 is directly connected with Host A, there should be an entry in the routing table like "C    192.168.10.34/24 is directly connected, FastEthernet0".  This means the packet is ready to be sent out from interface 192.168.10.33, which directly connects to the Host A 192.168.10.34. Notice hub don't have IP address, it is just a multi-port signal repeater.


• The router R4 get the hardware address for 192.168.10.34 with ARP process.


• The hardware address and packet are handed to the Data Link layer. The Data Link layer builds a frame with the destination address BBBB.3333.5677 and source hardware address 9999.DADC.1234 and then puts IP in the Ether-Type field. A CRC is run on the frame and the result is placed in the FCS field.


• The frame is then handed to the Physical layer to be sent out onto the local network one bit at a time.


• The destination Host A receives the frame, runs a CRC, checks the destination hardware address, and looks in the Ether-Type field to find out whom to hand the packet to.


• IP is the designated receiver, and after the packet is handed to IP at the Network layer, it checks the protocol field for further direction. IP finds instructions to give the payload to ICMP, and ICMP determines the packet to be an ICMP echo reply.


• ICMP acknowledges the ping program that it has received the reply, ping program then sends an exclamation point (!) to the user interface.


• ICMP then attempts to send four more echo requests to the destination host.

We have walked through the ping process step by step in the above demonstration. All these steps are hidden behind a single command "ping 192.168.10.134". As the packet traverses from router to router, layer 3 source and destination addresses do not change when the packet traverse, whereas layer 2 frame header and trailer are removed and replaced at every layer 3 device.

Module 2 Exam

1. Which layer of the OSI model provides network services to processes in electronic mail and file transfer programs?
• data link
• transport
• network
• application

2. Which of the following are data link layer encapsulation details? (Choose two.)
• A header and trailer are added.
• Data is converted into packets.
• Packets are packaged into frames.
• Frames are divided into segments.
• Packets are changed into bits for Internet travel.

3. Which three features apply to LAN connections? (Choose three.)
• operate using serial interfaces
• make network connection using a hub
• limited to operation over small geographic areas
• provide part-time connectivity to remote services
• typically operate under local administrative control
• provide lower bandwidth services compared to WANs

4. Which layer of the OSI model provides connectivity and path selection between two end systems where routing occurs?
• physical layer
• data link layer
• network layer
• transport layer

5. Which term describes the process of adding headers to data as it moves down OSI layers?
• division
• encoding
• separation
• segmentation
• encapsulation

6. Refer to the following list. Choose the correct order of data encapsulation when a device sends information.
1. segments
2. bits
3. packets
4. data
5. frames
• 1 – 3 – 5 – 4 – 2
• 2 – 1 – 3 – 5 – 4
• 2 – 4 – 3 – 5 – 1
• 4 – 3 – 1 – 2 – 5
• 4 – 1 – 3 – 5 – 2
• 3 – 5 – 1 – 2 – 4

7. The central hub has malfunctioned in the network. As a result, the entire network is down. Which type of physical network topology is implemented?
• bus
• star
• ring
• mesh

8. Which of the following are factors that determine throughput? (Choose two.)
• types of passwords used on servers
• type of Layer 3 protocol used
• network topology
• width of the network cable
• number of users on the network

9. Which best describes the function of the physical layer?
• Defines the electrical and functional specifications for the link between end systems.
• Provides reliable transit of data across a physical link.
• Provides connectivity and path selection between two end systems.
• Concerned with physical addressing, network topology and media access.

10. Which of the following are ways that bandwidth is commonly measured? (Choose three.)
• GHzps
• kbps
• Mbps
• Nbps
• MHzps
• Gbps

11. Which of the following are layers of the TCP/IP model? (Choose three.)
• Application
• Physical
• Internet
• Network Access
• Presentation

12. What is the term used to describe the transport layer protocol data unit?
• bits
• packets
• segments
• frames
• data streams

13. What makes it easier for different networking vendors to design software and hardware that will interoperate?
• OSI model
• proprietary designs
• IP addressing scheme
• standard logical topologies
• standard physical topologies

14.




 

Refer to the exhibit. Which column shows the correct sequence of OSI model layers?
• A
• B
• C
• D

15. What is one advantage of defining network communication by the seven layers of the OSI model?
• It increases the bandwidth of a network.
• It makes networking easier to learn and understand.
• It eliminates many protocol restrictions.
• It increases the throughput of a network.
• It reduces the need for testing network connectivity.

16. Which two features apply to WAN connections? (Choose two.)
• operate using serial interfaces
• make network connection using a hub
• limited to operation over small geographic areas
• typically operate under local administrative control
• provide lower bandwidth services compared to LANs

17. A switch has failed in the network. As a result, only one segment of the network is down. Which type of physical network topology is implemented?
• bus
• ring
• star
• extended star

18.



Refer to the exhibit. Identify the devices labeled A, B, C, and D in the network physical documentation.
• A=bridge, B=switch, C=router, D=hub
• A=bridge, B=hub, C=router, D=switch
• A=bridge, B=router, C=hub, D=switch
• A=hub, B=bridge, C=router, D=switch

Answers and Explains

Exam 5 -- 18 Question Set

Exam Source

Study Guides:

Lesson 1
Introduction to Networking and the Networking Models

Cover the theory needed for the exam, to accelerate Cisco networking career and for troubleshooting experience

* What is A Network?
* The OSI Model
* The Data Transmission Process
* The TCP/IP Model
* TCP And UDP
* Ports, Sockets and Port Numbers
* Network Topology

1. Which layer of the OSI model provides network services to processes in electronic mail and file transfer programs?
• data link
• transport
• network
• application

2. Which of the following are data link layer encapsulation details? (Choose two.)
• A header and trailer are added.
• Data is converted into packets.
• Packets are packaged into frames.
• Frames are divided into segments.
• Packets are changed into bits for Internet travel.

3. Which three features apply to LAN connections? (Choose three.)
• operate using serial interfaces
• make network connection using a hub
• limited to operation over small geographic areas
• provide part-time connectivity to remote services
• typically operate under local administrative control
• provide lower bandwidth services compared to WANs

4. Which layer of the OSI model provides connectivity and path selection between two end systems where routing occurs?
• physical layer
• data link layer
• network layer
• transport layer

5. Which term describes the process of adding headers to data as it moves down OSI layers?
• division
• encoding
• separation
• segmentation
• encapsulation

6. Refer to the following list. Choose the correct order of data encapsulation when a device sends information.
1. segments
2. bits
3. packets
4. data
5. frames
• 1 – 3 – 5 – 4 – 2
• 2 – 1 – 3 – 5 – 4
• 2 – 4 – 3 – 5 – 1
• 4 – 3 – 1 – 2 – 5
• 4 – 1 – 3 – 5 – 2
• 3 – 5 – 1 – 2 – 4

7. The central hub has malfunctioned in the network. As a result, the entire network is down. Which type of physical network topology is implemented?
• bus
• star
• ring
• mesh

8. Which of the following are factors that determine throughput? (Choose two.)
• types of passwords used on servers
• type of Layer 3 protocol used
• network topology
• width of the network cable
• number of users on the network

9. Which best describes the function of the physical layer?
• Defines the electrical and functional specifications for the link between end systems.
• Provides reliable transit of data across a physical link.
• Provides connectivity and path selection between two end systems.
• Concerned with physical addressing, network topology and media access.

10. Which of the following are ways that bandwidth is commonly measured? (Choose three.)
• GHzps
• kbps
• Mbps
• Nbps
• MHzps
• Gbps

11. Which of the following are layers of the TCP/IP model? (Choose three.)
• Application
• Physical
• Internet
• Network Access
• Presentation

12. What is the term used to describe the transport layer protocol data unit?
• bits
• packets
• segments
• frames
• data streams

13. What makes it easier for different networking vendors to design software and hardware that will interoperate?
• OSI model
• proprietary designs
• IP addressing scheme
• standard logical topologies
• standard physical topologies

14.

Refer to the exhibit. Which column shows the correct sequence of OSI model layers?
• A
• B
• C
• D

15. What is one advantage of defining network communication by the seven layers of the OSI model?
• It increases the bandwidth of a network.
• It makes networking easier to learn and understand.
• It eliminates many protocol restrictions.
• It increases the throughput of a network.
• It reduces the need for testing network connectivity.

16. Which two features apply to WAN connections? (Choose two.)
• operate using serial interfaces
• make network connection using a hub
• limited to operation over small geographic areas
• typically operate under local administrative control
• provide lower bandwidth services compared to LANs

17. A switch has failed in the network. As a result, only one segment of the network is down. Which type of physical network topology is implemented?
• bus
• ring
• star
• extended star

18.

Refer to the exhibit. Identify the devices labeled A, B, C, and D in the network physical documentation.
• A=bridge, B=switch, C=router, D=hub
• A=bridge, B=hub, C=router, D=switch
• A=bridge, B=router, C=hub, D=switch
• A=hub, B=bridge, C=router, D=switch

Modual 1 Exam

1. Several computers in the company require new NICs. A technician has located a good price on the Internet for the purchase of these NICs. Before these NICs are purchased and installed, what details must be verified? (Choose three.)
• the MAC address on
• the NICthe size of the RAM on the NIC
• the bandwidth supported by the NIC
• the type of media supported by the NIC
• the type of network architecture supported by the NIC

2. What is the hexadecimal equivalent for the binary number 00100101?
• 15
• 20
• 25
• 30
• 37
• 40

3. Which phrases describe a byte? (Choose two.)
• a single binary digit
• +5 volts of electricity
• the value range 0 to 127
• a grouping of eight binary digits
• a single addressable data storage location

4. Which specialized equipment is used to make a physical connection from a PC to a network?
• router
• RAM
• CD ROM
• network interface card

5. What is the binary equivalent for the decimal number 248?
• 11100000
• 11110000
• 11110100
• 11111000

6. Convert the binary number 01011011 into its hexadecimal equivalent.
Select the correct answer from the list below.
• 5A
• 5b
• 5c
• 5d
• 6b
• 7a

7. What is the binary equivalent for decimal number 149?
• 10010111
• 10010101
• 10011001
• 10010111
• 10101011
• 10101101

8. In an 8 bit binary number, what is the total number of combinations of the eight bits?
• 128
• 254
• 255
• 256
• 512
• 1024

9. Which device connects a computer with a telephone line by providing modulation and demodulation of incoming and outgoing data?
• NIC
• CSU/DSU
• router
• modem
• telco switch

10. What is the binary equivalent for the decimal number 162?
• 10101010
• 10100010
• 10100100
• 10101101
• 10110000
• 10101100

11. Which of the following are popular web browsers? (Choose two.)
• Acrobat
• Internet Explorer
• Macromedia Flash
• Netscape Navigator
• Quicktime
• World Wide Web

12. Convert the Base 10 number 116 into its eight bit binary equivalent. Choose the correct answer from the following list:
• 01111010
• 01110010
• 01110100
• 01110110
• 01110111
• 01010110

13. What is the hexadecimal equivalent for the binary number 10001110?
• 22
• 67
• 142
• AE
• 8E

14. Represented as a decimal number, what is the result of the logical ANDing of binary numbers 00100011 and 11111100?
• 3
• 32
• 35
• 220
• 255

15. Convert the decimal number 231 into its binary equivalent. Select the correct answer from the list below.
• 11110010
• 11011011
• 11110110
• 11100111
• 11100101
• 11101110

16. What are three conditions that would require a network administrator to install a new NIC? (Choose three.)
• whenever a NIC is damaged
• when there is a need to provide a secondary or backup NIC
• when there is a change from copper media to wireless
• whenever operating system security patches are applied
• whenever the PC has been moved to a different location

Answer and Explains

Exam 4 -- 16 Question Set

Exam Source

Study Guides:

* Decimal > Binary, Binary > Decimal

* Ethernet Addressing

1. Several computers in the company require new NICs. A technician has located a good price on the Internet for the purchase of these NICs. Before these NICs are purchased and installed, what details must be verified? (Choose three.)
• the MAC address on
• the NICthe size of the RAM on the NIC
• the bandwidth supported by the NIC
• the type of media supported by the NIC
• the type of network architecture supported by the NIC

2. What is the hexadecimal equivalent for the binary number 00100101?
• 15
• 20
• 25
• 30
• 37
• 40

3. Which phrases describe a byte? (Choose two.)
• a single binary digit
• +5 volts of electricity
• the value range 0 to 127
• a grouping of eight binary digits
• a single addressable data storage location

4. Which specialized equipment is used to make a physical connection from a PC to a network?
• router
• RAM
• CD ROM
• network interface card

5. What is the binary equivalent for the decimal number 248?
• 11100000
• 11110000
• 11110100
• 11111000

6. Convert the binary number 01011011 into its hexadecimal equivalent.
Select the correct answer from the list below.
• 5A
• 5b
• 5c
• 5d
• 6b
• 7a

7. What is the binary equivalent for decimal number 149?
• 10010111
• 10010101
• 10011001
• 10010111
• 10101011
• 10101101

8. In an 8 bit binary number, what is the total number of combinations of the eight bits?
• 128
• 254
• 255
• 256
• 512
• 1024

9. Which device connects a computer with a telephone line by providing modulation and demodulation of incoming and outgoing data?
• NIC
• CSU/DSU
• router
• modem
• telco switch

10. What is the binary equivalent for the decimal number 162?
• 10101010
• 10100010
• 10100100
• 10101101
• 10110000
• 10101100

11. Which of the following are popular web browsers? (Choose two.)
• Acrobat
• Internet Explorer
• Macromedia Flash
• Netscape Navigator
• Quicktime
• World Wide Web

12. Convert the Base 10 number 116 into its eight bit binary equivalent. Choose the correct answer from the following list:
• 01111010
• 01110010
• 01110100
• 01110110
• 01110111
• 01010110

13. What is the hexadecimal equivalent for the binary number 10001110?
• 22
• 67
• 142
• AE
• 8E

14. Represented as a decimal number, what is the result of the logical ANDing of binary numbers 00100011 and 11111100?
• 3
• 32
• 35
• 220
• 255

15. Convert the decimal number 231 into its binary equivalent. Select the correct answer from the list below.
• 11110010
• 11011011
• 11110110
• 11100111
• 11100101
• 11101110

16. What are three conditions that would require a network administrator to install a new NIC? (Choose three.)
• whenever a NIC is damaged
• when there is a need to provide a secondary or backup NIC
• when there is a change from copper media to wireless
• whenever operating system security patches are applied
• whenever the PC has been moved to a different location

CCENT Final Practice Exam 3 -- 51 Question Set

Exam: 640-822 Interconnecting Cisco Networking Devices Part 1 (ICND1)

Test time: 90 minutes.

Questions: 50-60 questions.

Pass Score: 80% correct.

Answers and Explainations

Exam: 640-822 Interconnecting Cisco Networking Devices Part 1 (ICND1)

Test time: 90 minutes.

Questions: 50-60 questions.

Pass Score: 80% correct.

Answers and Explainations

1. Which devices segment collision domains? (Choose two.)

a. transceiver
b. router
c. switch
d. hub
e. media

02. Which form of NAT maps multiple private IP addresses to a single registered IP address by using different ports?
(A) static NAT
(B) dynamic NAT
(C) overloading
(D) overlapping
(E) port loading

03. What should be part of a comprehensive network security plan?
(A) Allow users to develop their own approach to network security
(B) Physically secure network equipment from potential access by unauthorized individuals
(C) Encourage users to use personal information in their passwords to minimize the likelihood of passwords being forgotten
(D) Delay deployment of software patches and updates until their effect on end-user equipment is well known and widely reported
(E) Minimize network overhead by deactivating automatic antivirus client updates
 

04. Which of the following commands will configure a default route to any destination network not found in the routing table?
(A) Router(config)# ip default-route 0.0.0.0 255.255.255.255 s0
(B) Router(config)# ip route 0.0.0.0 255.255.255.255 s0
(C) Router(config)# ip default-route 0.0.0.0 s0
(D) Router(config)# ip route 0.0.0.0 0.0.0.0 s0
(E) Router(config)# ip route any any e0

05. For security reasons, information about RTA, including platform and IP addresses, should not be accessible from the Internet. This information should, however, be accessible to devices on the internal networks of RT A. Which command or series of commands will accomplish these objectives?
(A) RTA(config)#no cdp run
(B) RTA(config)#no cdp enable
(C) RTA(config)#interface s0/0
RTA(config-if)#no cdp run
(D) RTA(config)#interface s0/0
RTA(config-if)#no cdp enable
 

06. What is the purpose of flow control?
(A) to ensure data is retransmitted if an acknowledgment is not received
(B) to reassemble segments in the correct order at the destination device
(C) to provide a means for the receiver to govern the amount of data sent by the sender
(D) to regulate the size of each segment
 
7. A collision has occurred on an Ethernet network. Which three statements explain the CSMA/CD process? (Choose three.)

a. After the jam signal, all transmission stops for a random period.

b. When the collision is detected, the hosts stop transmission immediately.

c. When the collision is detected, the hosts stop transmission after eight microseconds.

d. When the backoff period expires, the hosts involved in the collision have priority to transmit.

e. When the backoff period expires, each host checks to see whether the networking media is idle and then attempts to transmit.

f. When the collision is detected, the hosts continue to transmit using a jam pattern for a short time to ensure that all hosts detect the collision.

8. Which of the following devices extend a collision domain? (Choose two.)

a. switch

b. hub

c. bridge

d. router

e. repeater

9. What should a network administrator consider when migrating to Gigabit Ethernet architecture from Fast Ethernet? (Choose three.)

a. Existing NICs might need to be upgraded.

b. Existing switches might need to be upgraded.

c. Existing NICs must support half-duplex mode.

d. Existing UTP wiring must be replaced with fiber.

e. Existing UTP must be tested for CAT 5e compatibility.

f. Existing network topology must support shared media.

10. which prompt is the global configuration mode on a Cisco router identified?
(A) Router>
(B) Router#
(C) Router(config)#
(D) Router(config-if)#
(E) Router(config-line)#c
(F) Router(config-router)#
 

11. Which binary number is a representation of the decimal number 248?

a. 11101000

b. 11110100

c. 11111000

d. 11111010

12. Which type of address is 223.168.17.167/29?

a. host address

b. multicast address

c. broadcast address

d. subnetwork address

13. Workstation A sends data to workstation B. What will have to be altered as the data passes through the router? (Choose two.)

a. Layer 1 bit pattern

b. Layer 2 frames

c. Layer 3 packets

d. Layer 4 segments

e. Layer 5 -7 data

14. Which combination of network id and subnet mask correctly identifies all IP addresses from 172.16.128.0 through 172.16.159.255?

a. 172.16.128.0 255.255.255.224

b. 172.16.128.0 255.255.0.0

c. 172.16.128.0 255.255.192.0

d. 172.16.128.0 255.255.224.0

e. 172.16.128.0 255.255.255.192

15. What is the correct number of usable subnetworks and hosts for the IP network address 192.168.99.0 subnetted with a /29 mask?

a. 6 networks / 32 hosts

b. 14 networks / 14 hosts

c. 30 networks / 6 hosts

d. 62 networks / 2 hosts

16. Which command is used on a Cisco router to reach the global configuration mode?
(A) Router> enable
(B) Router# router
(C) Router# setup
(D) Router# interface
(E) Router# configure terminal
17. A NIC of a computer has been assigned an IP address of 172.31.192.166 with a mask of 255.255.255.248. To which subnet does the IP address belong?

a. 172.31.0.0

b. 172.31.160.0

c. 172.31.192.0

d. 172.31.248.0

e. 172.31.192.160

f. 172.31.192.248

18. What are three characteristics of the TCP protocol? (Choose three.)

a. exchanges datagrams unreliably

b. is used to send IP error messages

c. forces the retransmission of unacknowledged packets

d. creates a virtual session between end-user applications

e. carries the IP address of the destination host in the TCP header

f. is responsible for breaking messages into segments and reassembling them at their destination

19. A network user is using the FTP protocol to transfer data from the local host to an FTP server. The local host is also using the SNMP protocol to report the system status to the network management system. Which statement describes the communication from the host?

a. FTP and SNMP will use the same port number.

b. FTP uses TCP to establish a session before any data is transferred.

c. The UDP session will reorder the SNMP data as it is received by the network management system.

d. The TCP protocol for the FTP transfer will use a random destination port number to the FTP server.

20. Which protocols are TCP/IP application layer protocols? (Choose two.)

a. UDP

b. FTP

c. IP

d. SMTP

e. TCP

21. Which technologies are considered to be WAN technologies? (Choose two.)

a. Ethernet

b. DSL

c. Token Ring

d. Frame Relay

e. FDDI
22. Serial0/0 does not respond to a ping request from a host on the FastEthernet0/0 LAN. How can this problem be corrected?
(A) Enable the Serial 0/0 interface
(B) Correct the IP address for Serial 0/0
(C) Correct the IP address for FastEthernet 0/0
(D) Change the encapsulation type on Serial 0/0
(E) Enable autoconfiguration on the Serial 0/0 interface
23. Why would a network administrator configure port security on a switch?
(A) to prevent unauthorized Telnet access to a switch port
(B) to limit the number of Layer 2 broadcasts on a particular switch port
(C) to prevent unauthorized hosts from accessing the LAN
(D) to protect the IP and MAC address of the switch and associated ports
(E) to block unauthorized access to the switch management interfaces over common TCP ports

24. Host A has established a communication session with host B for the first time. What enabled R1 to forward this traffic in the appropriate direction to reach the nework to which host B is attached?
(A) DNS
(B) DHCP
(C) TCP/IP
(D) a Layer 4 protocol
(E) a routing protocol
(F) a default gateway

25. When using Category 5 UTP cable, which RJ-45 pin pairs are used to exchange data between hosts on an Ethernet network?

a. 1 and 2; 4 and 5

b. 1 and 2; 3 and 6

c. 3 and 6; 7 and 8

d. 4 and 5; 7 and 8
26. What does the “Inside Global” address represent in the configuration of NAT?
(A) the summarized address for all of the internal subnetted addresses
(B) the MAC address of the router used by inside hosts to connect to the Internet
(C) a globally unique, private IP address assigned to a host on the inside network
(D) a registered address that represents an inside host to an outside network
27. How many simultaneous Telnet sessions does a Cisco router support by default?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5
(F) 6

28. Which cable diagram displays the end to end pinout for a console cable used with Cisco devices?

a. Cable A

b. Cable B

c. Cable C

d. Cable D

29. Which subnet masks would be valid for a subnetted Class B address? (Choose two.)

a. 255.0.0.0

b. 255.254.0.0

c. 255.224.0.0

d. 255.255.0.0

e. 255.255.252.0

f. 255.255.255.192

30. What type of routing is it when the network administrator manually configures a route?

a. static

b. dynamic

c. interior

d. exterior

31. Which statement describes a star topology?

a. Each host in the network is connected to a backbone cable that is terminated at both ends.

b. Each host is connected to a hub or switch, either of which acts as a central point for all network connections.

c. Each host is directly connected to two other hosts to form a long chain of hosts.

d. Each host has a connection to all other hosts in the network.

32. Host A is communicating with the server. What will be the source MAC address of the frames received by Host A from the server?
(A) the MAC address of router interface e0
(B) the MAC address of router interface e1
(C) the MAC address of the server network interface
(D) the MAC address of host A

33. A technician needs to connect a FastEthernet port from a router to a FastEthernet port on a switch. The graphic shows the RJ-45 cable ends for a patch cable. What result can be expected if this cable is used for the link?

a. The cable will be able to pass traffic between the devices.

b. The cable has reversed-pairs, which will degrade the signal quality.

c. The cable has split-pairs, which will increase crosstalk and create an unreliable link.

d. The cable has all the wires reversed, which will prevent the link lights from indicating that there is link.

34. Which IP address is a private address?
(A) 12.0.0.1
(B) 168.172.19.39
(C) 172.20.14.36
(D) 172.33.194.30
(E) 192.169.42.34

 

35. Which layer of the OSI model defines the process of adding the source and destination IP address to a data packet?

a. transport

b. network

c. data link

d. physical

36. Which encryption type does WPA2 use?
(A) AES-CCMP
(B) PPK via IV
(C) PSK
(D) TKIP/MIC

37. Which of the following protocols uses both TCP and UDP ports?
(A) FTP
(B) SMTP
(C) Telnet
(D) DNS

38. When the receiving workstation detects an error in the data it has received, it does not acknowledge receipt of the data. The source workstation retransmits the unacknowledged data. Which layer of the OSI model supports this process of retransmission?

a. network

b. application

c. session

d. transport

39. A company has the following addressing scheme requirements: -currently has 25 subnets -uses a Class B IP address -has a maximum of 300 computers on any network segment -needs to leave the fewest unused addresses in each subnetWhat subnet mask is appropriate to use in this company?

a. 255.255.240.0

b. 255.255.248.0

c. 255.255.254.0

d. 255.255.255.0

e. 255.255.255.128

f. 255.255.255.248

40. What can be verified by successfully pinging the reserved loopback address on a host?

a. Connectivity exists between two hosts on the LAN.

b. The TCP/IP stack of the local host is installed correctly.

c. A connection exists between a host and the default gateway.

d. The route a packet takes from the local host to a remote host is valid.

41. Three access points have been installed and configured to cover a small office. What term defines the wireless topology?
(A) BSS
(B) IBSS
(C) ESS
(D) SSID

42. Which command will set the default gateway to 192.168.12.1 on a Cisco switch?
(A) Switch(config)# ip default-network 192.168.12.1
(B) Switch(config)# ip route-default 192.168.12.1
(C) Switch(config)# ip default-gateway 192.168.12.1
(D) Switch(config)# ip route 192.168.12.1 0.0.0.0

43. A simplified CAM table for Switch1 is shown in the exhibit. If host A sends a frame with a destination MAC address of 66C, how does the switch process this frame?

a. The switch drops the frame.

b. The switch sends the frame out port 3.

c. The switch sends the frame out ports 1, 2, and 4.

d. The switch sends the frame out ports 2, 3, and 4.

e. The switch sends the frame out ports 1, 2, 3, and 4.

44. Which of the following increases the potential for a collision to occur?

a. the use of an active hub instead of an intelligent hub

b. the use of an intelligent hub instead of an active hub

c. a reduction in the number of devices attached to the hub

d. an increase in the number of devices attached to the hub

45. What is the effect of using the service password-encryption command?
(A) Only the enable password will be encrypted
(B) Only the enable secret password will be encrypted
(C) Only passwords configured after the command has been entered will be encrypted
(D) It will encrypt the secret password and remove the enable secret password from the configuration
(E) It will encrypt all current and future passwords
 

46. A workstation is browsing a web server. What will be the partial contents of the segment sent from the workstation to the web server?

a. Gambar 1

b. Gambar 2

c. Gambar 3

d. Gambar 4

47. What is the purpose of a default route?
(A) It is a route to be used when the routing protocol fails
(B) It is a route configured by an ISP that sends traffic into a corporate network
(C) It is a route used when a packet is destined for a remote network that is not listed in the routing table.
(D) It is a route manually configured for a specific remote network for which a routing protocol is not configured.
(E) It is used to send traffic to a stub network.
48. Workstation A must be able to telnet to switch SW-A through router RTA for management purposes. What must be configured for this connection to be successful?
(A) VLAN 1 on RTA
(B) default gateway on SW-A
(C) IP routing on SW-A
(D) cross-over cable connecting SW-A and RTA

49. A user initiates three simultaneous FTP connections from the local host to the same FTP server. Which OSI layer is responsible for establishing and managing these different FTP connections?

a. application

b. session

c. transport

d. network

e. data link

50. At which layer of the OSI model does the protocol that provides the information displayed by the show cdp neighbors command operate?
(A) physical
(B) data link
(C) network
(D) transport
(E) application

51. Serial0/0 does not respond to a ping request from a host on the FastEthernet0/0 LAN. How can this problem be corrected?
(A) Enable the Serial 0/0 interface
(B) Correct the IP address for Serial 0/0
(C) Correct the IP address for FastEthernet 0/0
(D) Change the encapsulation type on Serial 0/0
(E) Enable autoconfiguration on the Serial 0/0 interface

CCENT Final Exam 3 -- 51 question set

Exam Source

1. Which devices segment collision domains? (Choose two.)

a. transceiver
#b. router
#c. switch
d. hub
e. media

02. Which form of NAT maps multiple private IP addresses to a single registered IP address by using different ports?
(A) static NAT
(B) dynamic NAT
#(C) overloading
(D) overlapping
(E) port loading

03. What should be part of a comprehensive network security plan?
(A) Allow users to develop their own approach to network security
#(B) Physically secure network equipment from potential access by unauthorized individuals
(C) Encourage users to use personal information in their passwords to minimize the likelihood of passwords being forgotten
(D) Delay deployment of software patches and updates until their effect on end-user equipment is well known and widely reported
(E) Minimize network overhead by deactivating automatic antivirus client updates
 

04. Which of the following commands will configure a default route to any destination network not found in the routing table?
(A) Router(config)# ip default-route 0.0.0.0 255.255.255.255 s0
(B) Router(config)# ip route 0.0.0.0 255.255.255.255 s0
(C) Router(config)# ip default-route 0.0.0.0 s0
#(D) Router(config)# ip route 0.0.0.0 0.0.0.0 s0
(E) Router(config)# ip route any any e0

05. For security reasons, information about RTA, including platform and IP addresses, should not be accessible from the Internet. This information should, however, be accessible to devices on the internal networks of RT A. Which command or series of commands will accomplish these objectives?
(A) RTA(config)#no cdp run
(B) RTA(config)#no cdp enable
(C) RTA(config)#interface s0/0
RTA(config-if)#no cdp run
#(D) RTA(config)#interface s0/0
RTA(config-if)#no cdp enable
 

06. What is the purpose of flow control?
(A) to ensure data is retransmitted if an acknowledgment is not received
(B) to reassemble segments in the correct order at the destination device
#(C) to provide a means for the receiver to govern the amount of data sent by the sender
(D) to regulate the size of each segment

7. A collision has occurred on an Ethernet network. Which three statements explain the CSMA/CD process? (Choose three.)

#a. After the jam signal, all transmission stops for a random period.

b. When the collision is detected, the hosts stop transmission immediately.

c. When the collision is detected, the hosts stop transmission after eight microseconds.

d. When the backoff period expires, the hosts involved in the collision have priority to transmit.

#e. When the backoff period expires, each host checks to see whether the networking media is idle and then attempts to transmit.

#f. When the collision is detected, the hosts continue to transmit using a jam pattern for a short time to ensure that all hosts detect the collision.

8. Which of the following devices extend a collision domain? (Choose two.)

a. switch

#b. hub

c. bridge

#d. router

e. repeater

9. What should a network administrator consider when migrating to Gigabit Ethernet architecture from Fast Ethernet? (Choose three.)

#a. Existing NICs might need to be upgraded.

#b. Existing switches might need to be upgraded.

c. Existing NICs must support half-duplex mode.

d. Existing UTP wiring must be replaced with fiber.

e. Existing UTP must be tested for CAT 5e compatibility.

f. Existing network topology must support shared media.

10. which prompt is the global configuration mode on a Cisco router identified?
(A) Router>
(B) Router#
#(C) Router(config)#
(D) Router(config-if)#
(E) Router(config-line)#c
(F) Router(config-router)#

11. Which binary number is a representation of the decimal number 248?

a. 11101000

b. 11110100

#c. 11111000

d. 11111010

12. Which type of address is 223.168.17.167/29?

a. host address

b. multicast address

c. broadcast address

d. subnetwork address

13. Workstation A sends data to workstation B. What will have to be altered as the data passes through the router? (Choose two.)

#a. Layer 1 bit pattern

#b. Layer 2 frames

c. Layer 3 packets

d. Layer 4 segments

e. Layer 5 -7 data

14. Which combination of network id and subnet mask correctly identifies all IP addresses from 172.16.128.0 through 172.16.159.255?

a. 172.16.128.0 255.255.255.224

b. 172.16.128.0 255.255.0.0

c. 172.16.128.0 255.255.192.0

#d. 172.16.128.0 255.255.224.0

e. 172.16.128.0 255.255.255.192

15. What is the correct number of usable subnetworks and hosts for the IP network address 192.168.99.0 subnetted with a /29 mask?

a. 6 networks / 32 hosts

b. 14 networks / 14 hosts

#c. 30 networks / 6 hosts

d. 62 networks / 2 hosts

16. Which command is used on a Cisco router to reach the global configuration mode?
(A) Router> enable
(B) Router# router
(C) Router# setup
(D) Router# interface
#(E) Router# configure terminal

17. A NIC of a computer has been assigned an IP address of 172.31.192.166 with a mask of 255.255.255.248. To which subnet does the IP address belong?

a. 172.31.0.0

b. 172.31.160.0

c. 172.31.192.0

d. 172.31.248.0

#e. 172.31.192.160

f. 172.31.192.248

18. What are three characteristics of the TCP protocol? (Choose three.)

#a. exchanges datagrams unreliably

#b. is used to send IP error messages

c. forces the retransmission of unacknowledged packets

d. creates a virtual session between end-user applications

#e. carries the IP address of the destination host in the TCP header

f. is responsible for breaking messages into segments and reassembling them at their destination

19. A network user is using the FTP protocol to transfer data from the local host to an FTP server. The local host is also using the SNMP protocol to report the system status to the network management system. Which statement describes the communication from the host?

a. FTP and SNMP will use the same port number.

#b. FTP uses TCP to establish a session before any data is transferred.

c. The UDP session will reorder the SNMP data as it is received by the network management system.

d. The TCP protocol for the FTP transfer will use a random destination port number to the FTP server.

20. Which protocols are TCP/IP application layer protocols? (Choose two.)

a. UDP

#b. FTP

c. IP

#d. SMTP

e. TCP

21. Which technologies are considered to be WAN technologies? (Choose two.)

a. Ethernet

#b. DSL

c. Token Ring

#d. Frame Relay

e. FDDI

22. Serial0/0 does not respond to a ping request from a host on the FastEthernet0/0 LAN. How can this problem be corrected?
#(A) Enable the Serial 0/0 interface
(B) Correct the IP address for Serial 0/0
(C) Correct the IP address for FastEthernet 0/0
(D) Change the encapsulation type on Serial 0/0
(E) Enable autoconfiguration on the Serial 0/0 interface
23. Why would a network administrator configure port security on a switch?
(A) to prevent unauthorized Telnet access to a switch port
(B) to limit the number of Layer 2 broadcasts on a particular switch port
#(C) to prevent unauthorized hosts from accessing the LAN
(D) to protect the IP and MAC address of the switch and associated ports
(E) to block unauthorized access to the switch management interfaces over common TCP ports

24. Host A has established a communication session with host B for the first time. What enabled R1 to forward this traffic in the appropriate direction to reach the nework to which host B is attached?
(A) DNS
(B) DHCP
(C) TCP/IP
(D) a Layer 4 protocol
#(E) a routing protocol
(F) a default gateway

25. When using Category 5 UTP cable, which RJ-45 pin pairs are used to exchange data between hosts on an Ethernet network?

a. 1 and 2; 4 and 5

#b. 1 and 2; 3 and 6

c. 3 and 6; 7 and 8

d. 4 and 5; 7 and 8

26. What does the “Inside Global” address represent in the configuration of NAT?
(A) the summarized address for all of the internal subnetted addresses
(B) the MAC address of the router used by inside hosts to connect to the Internet
(C) a globally unique, private IP address assigned to a host on the inside network
#(D) a registered address that represents an inside host to an outside network
27. How many simultaneous Telnet sessions does a Cisco router support by default?
(A) 1
(B) 2
(C) 3
(D) 4
#(E) 5
(F) 6

28. Which cable diagram displays the end to end pinout for a console cable used with Cisco devices?

a. Cable A

#b. Cable B

c. Cable C

d. Cable D

29. Which subnet masks would be valid for a subnetted Class B address? (Choose two.)

a. 255.0.0.0

b. 255.254.0.0

c. 255.224.0.0

d. 255.255.0.0

#e. 255.255.252.0

#f. 255.255.255.192

30. What type of routing is it when the network administrator manually configures a route?

#a. static

b. dynamic

c. interior

d. exterior

31. Which statement describes a star topology?

a. Each host in the network is connected to a backbone cable that is terminated at both ends.

#b. Each host is connected to a hub or switch, either of which acts as a central point for all network connections.

c. Each host is directly connected to two other hosts to form a long chain of hosts.

d. Each host has a connection to all other hosts in the network.

32. Host A is communicating with the server. What will be the source MAC address of the frames received by Host A from the server?
#(A) the MAC address of router interface e0
(B) the MAC address of router interface e1
(C) the MAC address of the server network interface
(D) the MAC address of host A

33. A technician needs to connect a FastEthernet port from a router to a FastEthernet port on a switch. The graphic shows the RJ-45 cable ends for a patch cable. What result can be expected if this cable is used for the link?

#a. The cable will be able to pass traffic between the devices.

b. The cable has reversed-pairs, which will degrade the signal quality.

c. The cable has split-pairs, which will increase crosstalk and create an unreliable link.

d. The cable has all the wires reversed, which will prevent the link lights from indicating that there is link.

34. Which IP address is a private address?
(A) 12.0.0.1
(B) 168.172.19.39
#(C) 172.20.14.36
(D) 172.33.194.30
(E) 192.169.42.34

35. Which layer of the OSI model defines the process of adding the source and destination IP address to a data packet?

a. transport

#b. network

c. data link

d. physical

36. Which encryption type does WPA2 use?
#(A) AES-CCMP
(B) PPK via IV
(C) PSK
(D) TKIP/MIC

37. Which of the following protocols uses both TCP and UDP ports?
(A) FTP
(B) SMTP
(C) Telnet
#(D) DNS

38. When the receiving workstation detects an error in the data it has received, it does not acknowledge receipt of the data. The source workstation retransmits the unacknowledged data. Which layer of the OSI model supports this process of retransmission?

a. network

b. application

c. session

#d. transport

39. A company has the following addressing scheme requirements: -currently has 25 subnets -uses a Class B IP address -has a maximum of 300 computers on any network segment -needs to leave the fewest unused addresses in each subnetWhat subnet mask is appropriate to use in this company?

a. 255.255.240.0

b. 255.255.248.0

#c. 255.255.254.0

d. 255.255.255.0

e. 255.255.255.128

f. 255.255.255.248

40. What can be verified by successfully pinging the reserved loopback address on a host?

a. Connectivity exists between two hosts on the LAN.

#b. The TCP/IP stack of the local host is installed correctly.

c. A connection exists between a host and the default gateway.

d. The route a packet takes from the local host to a remote host is valid.

41. Three access points have been installed and configured to cover a small office. What term defines the wireless topology?
(A) BSS
(B) IBSS
#(C) ESS
(D) SSID

42. Which command will set the default gateway to 192.168.12.1 on a Cisco switch?
(A) Switch(config)# ip default-network 192.168.12.1
(B) Switch(config)# ip route-default 192.168.12.1
#(C) Switch(config)# ip default-gateway 192.168.12.1
(D) Switch(config)# ip route 192.168.12.1 0.0.0.0

43. A simplified CAM table for Switch1 is shown in the exhibit. If host A sends a frame with a destination MAC address of 66C, how does the switch process this frame?

a. The switch drops the frame.

b. The switch sends the frame out port 3.

c. The switch sends the frame out ports 1, 2, and 4.

#d. The switch sends the frame out ports 2, 3, and 4.

e. The switch sends the frame out ports 1, 2, 3, and 4.

44. Which of the following increases the potential for a collision to occur?

a. the use of an active hub instead of an intelligent hub

b. the use of an intelligent hub instead of an active hub

c. a reduction in the number of devices attached to the hub

#d. an increase in the number of devices attached to the hub

45. What is the effect of using the service password-encryption command?
(A) Only the enable password will be encrypted
(B) Only the enable secret password will be encrypted
(C) Only passwords configured after the command has been entered will be encrypted
(D) It will encrypt the secret password and remove the enable secret password from the configuration
#(E) It will encrypt all current and future passwords
 

46. A workstation is browsing a web server. What will be the partial contents of the segment sent from the workstation to the web server?

#a. Gambar 1

b. Gambar 2

c. Gambar 3

d. Gambar 4

47. What is the purpose of a default route?
(A) It is a route to be used when the routing protocol fails
(B) It is a route configured by an ISP that sends traffic into a corporate network
#(C) It is a route used when a packet is destined for a remote network that is not listed in the routing table.
(D) It is a route manually configured for a specific remote network for which a routing protocol is not configured.
(E) It is used to send traffic to a stub network.
48. Workstation A must be able to telnet to switch SW-A through router RTA for management purposes. What must be configured for this connection to be successful?
(A) VLAN 1 on RTA
#(B) default gateway on SW-A
(C) IP routing on SW-A
(D) cross-over cable connecting SW-A and RTA

49. A user initiates three simultaneous FTP connections from the local host to the same FTP server. Which OSI layer is responsible for establishing and managing these different FTP connections?

a. application

#b. session

c. transport

d. network

e. data link

50. At which layer of the OSI model does the protocol that provides the information displayed by the show cdp neighbors command operate?
(A) physical
#(B) data link
(C) network
(D) transport
(E) application

51. Serial0/0 does not respond to a ping request from a host on the FastEthernet0/0 LAN. How can this problem be corrected?
#(A) Enable the Serial 0/0 interface
(B) Correct the IP address for Serial 0/0
(C) Correct the IP address for FastEthernet 0/0
(D) Change the encapsulation type on Serial 0/0
(E) Enable autoconfiguration on the Serial 0/0 interface

CCENT Final Exam 2 - 50 question set

Exam Source

Question 1: (QID=25141)

Which DHCP message is sent as a broadcast on the network?

1. DHCP Discover

2. DHCP Offer

3. DHCP Request

4. DHCP Acknowledgement

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

Correct answer(s): 1

Explanation: The DHCP Discover message is sent as a broadcast on the network.

[Implement an IP addressing scheme and IP services to meet network requirements for a small branch office]

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

Question 2: (QID=2352)

Given the following IP Address 172.45.34.1/24. What is the network and host portion?

1. Network 172.45.34 Host 1

2. Network 172 Host 45.34.1

3. Network 172.45 Host 34.1

4. This is an invalid IP Address

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

Correct answer(s): 1

Explanation: 172.45.34.1/24 is the same as 172.45.34.1 255.255.255.0. So we can see from the subnet mask that the first 3 octets belong to the network portion of the IP Address and the 4th octet is the host portion.

[Implement an IP addressing scheme and IP services to meet network requirements for a small branch office]

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

Question 3: (QID=25120)

You want to use RIPv2 as your routing protocol. Which commands will enable RIPv2 on your router?

A

router#configure terminal

router (config)#router rip version2

router(config-router)#network 10.0.0.0

router(config-router)#network 172.16.0.0

router(config-router)#^Z

B

router#router rip

router(config-router)#network 10.0.0.0

router(config-router)#network 172.16.0.0

router(config-router)#^Z

C

router#configure terminal

router(config)#router rip v2

router(config-router)#network 10.0.0.0

router(config-router)#network 172.16.0.0

router(config-router)#^Z

D

router#configure terminal

router(config)#router rip

router(config-router)#version 2

router(config-router)#network 10.0.0.0

router(config-router)#network 172.16.0.0

router(config-router)#^Z

1. A

2. B

3. C

4. D

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

Correct answer(s): 4

Explanation: Only three steps are necessary to configure RIPv2:

Enable RIP with the command router rip.

Specify the version with the version 2 command

Specify each major network on which to run RIP with the network command.

[Implement a small routed network]

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

Question 4: (QID=25125)

You want to implement port-security on your 2960 but you don’t know all of the MAC addresses. How can you still enable port-security and protect the currently attached devices?

1. switch(config-if)#switchport port-security mac-address sticky

2. switch(config-if)#switchport port-security mac-address enable

3. switch(config-if)#switchport port-security mac-address learn

4. switch(config-if)#switchport port-security mac-address dynamic

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

Correct answer(s): 1

Explanation: When we use the switchport port-security mac-address sticky interface configuration command the switch looks at the the header of the first frame to determine the mac-address of the host that is currently connected to that port.

[Implement a small switched network]

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

Question 5: (QID=25121)

How do you enable ppp on a serial interface?

1. router(config)#ppp enable

2. router(config-if)#encapsulation ppp

3. router(config-if)#ppp enable

4. router(config-if)#no encapsulation hdlc

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

Correct answer(s): 2

Explanation: The encapsulation ppp interface configuration command enables ppp on the interface.

[Implement and verify WAN links]

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

Question 6: (QID=2368)

What command do we use if we want to discover other Cisco devices on the network?

1. Discover neighbors

2. Show neighbors

3. CDP run

4. CDP enable

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

Correct answer(s): 3

Explanation: To enable Cisco Discovery Protocol (CDP), use the cdp run global configuration command. To disable CDP, use the no form of this command.

no cdp run

[Implement a small switched network]

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

Question 7: (QID=1323)

Spanning Tree is used in a switched network to:

1. Create a loop-free switched network

2. Manage a switched network

3. Avoid collisions on the switched network

4. Route between VLAN’s

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

Correct answer(s): 1

Explanation: Spanning Tree is a technology that allows bridges to communicate with each other to discover physical loops in the network. The protocol then specifies an algorithm that bridges use to create a loop-free logical topology.

[Implement a small switched network]

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

Question 8: (QID=3620)

What switching method is described by the following:

"The switch receives the entire frame and calculates a CRC. This method has high latency because of this behaviour."

1. Cut-Through

2. Cisco Express Forwarding

3. Fragment-Free

4. Store-and-Forward

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

Correct answer(s): 4

Explanation: The Store-and-Forward switching mode receives the entire frame before beginning the switching process. When it receives the complete frame, the switch examines it for the source and destination addresses and any errors it may contain, and then it possibly applies any special filters created by the network administrator to modify the default behaviour. If the switch observes any errors in the frame, it is discarded, preventing errored frames from consuming bandwidth on the destination segment.

[Implement a small switched network]

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

Question 9: (QID=2365)

What command is used during an IOS upgrade to place the IOS image on the router?

1. Show version

2. Copy TFTP: Flash:

3. Copy TFTP: RAM:

4. Copy running-config startup-config

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

Correct answer(s): 2

Explanation: Router Memory Commands

[Implement a small routed network]

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

Question 10: (QID=2380)

Which command do we use to move from interface configuration mode to global configuration mode without exiting configuration mode?

1. Disable

2. Logout

3. End

4. Exit

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

Correct answer(s): 4

Explanation: Click here for more information.

[Implement a small switched network]

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

Question 11: (QID=25131)

In 802.11b, how many non-overlapping channels are available?

1. 1

2. 3

3. 5

4. 7

5. 11

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

Correct answer(s): 2

Explanation: 802.11b has 3 non-overlapping channels, channel 1, 6 and 11

[Explain and select the appropriate administrative tasks required for a WLAN]

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

Question 12: (QID=2999)

What command do we use if we want to see the output of our debugs during our session?

1. Show debug all

2. u all

3. Terminal monitor

4. Show all debug

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

Correct answer(s): 3

Explanation: The terminal monitor command in EXEC mode will display all debug outputs and system error messages for the current terminal and session.

[Implement a small switched network]

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

Question 13: (QID=2996)

You have lost telnet access to your switch which is located on-site. When trying to access the switch via the console port we are unable to get a connection going. Our terminal emulation program settings are: 9600 baud, 8N1, no flow-control. What could be the cause of the problem?

1. We are using a cross-over cable

2. We are using a roll-over cable

3. Our terminal emulation program is not configured correctly

4. The operating system on our PC/laptop is not compatible with Cisco

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

Correct answer(s): 1

Explanation: In order to use the console port on a router we need to configure our Terminal Emulation program (Hyper Terminal, TerraTerm Pro, …) with the following parameters:

Baud rate: 9600

Data bits:8

Parity: none

Stop bits: 1

Flow control: none

The cable type we use is a cross-over cable. [Implement a small switched network]

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

Question 14: (QID=25139)

What can we use to detect an attack that has a specific packet pattern?

1. Firewall

2. IPS

3. Anti-virus

4. URL filtering

5. DMZ

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

Correct answer(s): 2

Explanation: An IPS, Intrusion Prevention System or IDS, Intrusion Detection System, is used to detect/prevent attacks that have a distinctive packet pattern.

[Identify security threats to a network and describe general methods to mitigate those threats]

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

Question 15: (QID=1324)

According to the IEEE 802.3 standard, Ethernet can run on what type of media? [Select all that apply]

1. 10BaseF

2. 100BaseTX

3. 1000BaseF

4. 10Base5

5. 10Base4

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

Correct answer(s): 1 4

Explanation: 10BaseT - Ethernet over Twisted Pair Media

10BaseF - Ethernet over Fiber Media

10Base2 - Ethernet over Thin Coaxial Media

10Base5 - Ethernet over Thick Coaxial Media

[Implement a small switched network]

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

Question 16: (QID=25127)

Which of the following encourages the interoperability of wireless products?

1. IEEE

2. FCC

3. Wi-Fi alliance

4. ITU-R

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

Correct answer(s): 3

Explanation: The Wi-Fi alliance encourages the interoperability of wireless products using their Wi-Fi certified program.

[Explain and select the appropriate administrative tasks required for a WLAN]

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

Question 17: (QID=2383)

Which of the following describes the correct order when a router is powered on?

1. Locate the IOS image, hardware is initialized, load configuration file, decompress the IOS image

2. Load configuration file, hardware is initialized, locate the IOS image, decompress the IOS image

3. Locate the IOS image, decompress the IOS image, hardware is initialized, load configuration file

4. Hardware is initialized, locate the IOS image, decompress the IOS image, load configuration file

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

Correct answer(s): 4

Explanation: The boot sequence of a Cisco router is as follows:

ROM Monitor is the first to start and together with the BOOTSTRAP the following functions are performed:

Power-on register settings are configured

NVRAM and DRAM is tested

Hardware is initialized

Software structures are initialized

ROMmon looks for the IOS image in the flash

Once the IOS image is located the router decompresses it and loads it into DRAM. The IOS itself performs the following functions:

recognition of interfaces and other hardware

setting up proper data structures

allocating buffers

loading the configuration file from NVRAM to RAM

[Implement a small routed network]

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

Question 18: (QID=3680)

When our information is travelling down the OSI model what name do we give it when it reaches layer 3?

1. Frames

2. Segments

3. Bits

4. Packets

5. Data

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

Correct answer(s): 4

Explanation: When user data travels through the OSI layers each layer adds its own information to the data. User data is called ‘Data’ at the application, presentation and session layer, when it moves through the transport layer it is called ‘Segments’. Packets can be found at the network layer of the OSI model. At layer 2 or Datalink layer we are talking about ‘Frames’ that will be put on the wire at the physical layer in the form of ‘Bits’.

[Describe the operation of data networks]

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

Question 19: (QID=25135)

Which of the following are parts of a socket?

1. IP address

2. Transport protocol

3. Sequence number

4. Port number

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

Correct answer(s): 1 2 4

Explanation: A socket has three parts:

IP Address

Transport protocol (TCP or UDP)

Port number

[Describe the operation of data networks]

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

Question 20: (QID=3677)

What protocol is used to resolve MAC Addresses to a known IP Address?

1. ICMP

2. RARP

3. IGMP

4. ARP

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

Correct answer(s): 4

Explanation: A host that wants to communicate with another host of which the IP Address is known will send out an ARP request to discover the MAC Address.

[Implement an IP addressing scheme and IP services to meet network requirements for a small branch office]

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

Question 21: (QID=2338)

What type of connection do you recommended for the following scenario: The remote sites need fast downloads while their uploads to the head office can be slower, cost has to be taken into account.

1. ATM

2. ISDN

3. Frame-Relay

4. ADSL

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

Correct answer(s): 4

Explanation: Asymmetric Digital Subscriber Line. One of four DSL technologies. ADSL is designed to deliver more bandwidth downstream (from the central office to the customer site) than upstream. Downstream rates range from 1.5 to 9 Mbps, whereas upstream bandwidth ranges from 16 to 640 kbps. ADSL transmissions work at distances up to 18,000 feet (5,488 meters) over a single copper twisted pair.

[Describe the operation of data networks]

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

Question 22: (QID=3006)

One of the software engineers in the company wants to test a new application. When he connects the PC to a free port on the switch he does not get a link light. When he temporarily connects the PC to a different port there is a link light. What is the most likely cause of this problem?

1. The NIC in the PC is 100Mb and the switch port is configured for 10MB

2. All the switch ports are faulty

3. The application is not working properly

4. The cable is faulty

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

Correct answer(s): 1

Explanation: Because there is a speed mismatch between the PC and the switch port a link will not be established.

[Implement a small switched network]

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

Question 23: (QID=2376)

We want to configure a password in order to secure the Privileged EXEC mode? Which of the following are commands we can use?

1. Password enable password

2. Enable password password

3. Secret Password password

4. Enable Secret password

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

Correct answer(s): 2 4

Explanation: To set a local password to control access to various privilege levels, use the enable password command in global configuration mode. To specify an additional layer of security over the enable password command, use the enable secret command in global configuration mode.

[Implement a small routed network]

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

Question 24: (QID=2373)

We want to know which routing protocols are active on the router. Which command do we use?

1. Show IP Protocols

2. Show IP Routing Protocols

3. Show Active Protocols

4. Show IP Active Protocols

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

Correct answer(s): 1

Explanation: To display the parameters and current state of the active routing protocol process, use the show ip protocols command in privileged EXEC mode.

[Implement a small routed network]

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

Question 25: (QID=3611)

Users complain that they are not able access resources at the head office. You ping a few hosts on the head office LAN and the responses are all unsuccessful. What would be the next step you do to locate the problem?

1. Use the trace route utility

2. Reboot the router

3. Clear the routing table

4. Replace the faulty router

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

Correct answer(s): 1

Explanation: When we use the trace route utility to one of the IP Addresses we pinged we will find out at which hop the problem lies. We then can continue our troubleshooting from that point.

[Implement a small routed network]

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

Question 26: (QID=2988)

Which of the following commands would you use to troubleshoot a routing problem?

1. Show version

2. Show IP route

3. Show IP interface brief

4. Ping

5. Show users

6. Traceroute

7. Show hosts

8. Show history

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

Correct answer(s): 2 4 6

Explanation: When troubleshooting a routing issue we usually start by ‘pinging’ a host on the remote network we try to reach. If we don’t get a response back we check the routing table to see if we have a route to the remote network. If there is a route we do a ‘traceroute’ to the remote network to find out at which hop the possible cause of the problem might lie.

Understanding the Ping and Traceroute Commands Troubleshooting Tools

[Implement a small routed network]

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

Question 27: (QID=2989)

What command do we use to show us all the RIP entries in the routing table but no other routes?

1. Show ip route

2. Show ip rip route

3. Show rip route

4. Show ip route rip

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

Correct answer(s): 4

Explanation: The show ip route command can be ‘extended’ with the name of the routing protocol running on the router. Adding the name of the routing protocol displays only entries of that protocol in the routing table.

[Implement a small routed network]

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

Question 28: (QID=25132)

Which of the following wireless parameters has to be the same on both the client and AP?

1. SSID

2. ESS

3. radio power setting

4. BSS

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

Correct answer(s): 1

Explanation: In order to get an association with the AP the SSID, Service Set Identifier, has to be same on the AP and wireless client.

[Explain and select the appropriate administrative tasks required for a WLAN]

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

Question 29: (QID=3683)



Look at the network topology in the exhibit. How many collision domains are there?

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

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

Correct answer(s): 5

Explanation: A Collision Domain is defined as all of the Ethernet segments between a pair of bridges or other layer 2 devices.



[Implement a small switched network]

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

Question 30: (QID=2367)

After making configuration changes, you want to save them. What command do you use? [Select best answer]

1. Save config

2. write memory

3. Copy startup-config running-config

4. Copy running-config startup-config

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

Correct answer(s): 4

Explanation: Copy running-config startup-config will save your changes to NVRAM. Although write memory will do the same thing it is better to use the copy command.

[Implement a small switched network]

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

Question 31: (QID=1295)

RIP Version 2 uses which multicast address to update its routing tables.

1. 224.0.0.10

2. 224.0.0.5

3. 224.0.0.1

4. 224.0.0.9

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

Correct answer(s): 4

Explanation: More information about RIP version 2 can be found at RIP Version 2 RFC 2453. The other multicast addresses are used by different routing protocols (EIGRP, OSPF).

[Implement a small routed network]

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

Question 32: (QID=25146)

Which proprietary Cisco field is added to the HDLC standard frame?

1. Type

2. Flag

3. Destination

4. Control

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

Correct answer(s): 1

Explanation: Cisco added a type field to the HDLC standard frame to make it Cisco proprietary.

[Implement and verify WAN links]

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

Question 33: (QID=2377)

What command do we use to show us a summary of the all the interfaces on a router?

1. Show IP interface brief

2. Show interfaces all

3. Show IP interface detail

4. Show interfaces brief

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

Correct answer(s): 1

Explanation: The show ip interface brief command will give you all the interfaces of the router and their status, IP Address, etc… This command can be useful troubleshooting tool if you quickly want to view the interface details.

click here for sample output of this command.

[Implement a small routed network]

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

Question 34: (QID=3623)

Which switching method will store the first 64 bytes of the packet?

1. Store-and-Forward

2. Cut-Through

3. Cisco Express Forwarding

4. Fragment-Free

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

Correct answer(s): 4

Explanation: A less common method is fragment-free. It works like cut-through but stores the first 64 bytes of the packet before sending it on. The reason for this is that most errors and all collisions occur during the initial 64 bytes of a packet.

[Implement a small switched network]

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

Question 35: (QID=2358)

When implementing a switched network we have to make sure that the following is running?

1. VTP Pruning

2. IGMP

3. A routing protocol

4. Spanning Tree

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

Correct answer(s): 4

Explanation: Spanning tree will provide a loop free switched environment.

[Implement a small switched network]

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

Question 36: (QID=3624)

Which port does TFTP use?

1. 53

2. 21

3. 69

4. 20

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

Correct answer(s): 3

Explanation: TFPT uses port 69. Well-known Port Numbers

[Describe the operation of data networks]

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

Question 37: (QID=1285)

What is the administrative distance of the following Static Route:

IP Route 192.168.3.0 255.255.255.0 Serial0/1

1. 1

2. 110

3. 0

4. 255

5. 170

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

Correct answer(s): 3

Explanation: Static routes using an exit interface have an administrative distance of 0. Administrative Distance.

[Implement a small routed network]

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

Question 38: (QID=25129)

Which two modes exist in a wireless network?

1. Ad-hoc mode

2. Peer-to-peer mode

3. Shared mode

4. Infrastructure mode

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

Correct answer(s): 1 4

Explanation: Wireless networks operate either in Ad-Hoc mode or Infrastructure mode.

[Explain and select the appropriate administrative tasks required for a WLAN]

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

Question 39: (QID=3631)

In which of the following configurations would you use a crossover cable?

1. Host to switch

2. Switch to router

3. Host to router

4. Hub to Switch

5. Hosts to hub

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

Correct answer(s): 3 4

Explanation: Crossover cables can be used in the following situations:

to connect 2 hosts together

to connect 2 switches or hubs

to connect a router to a host

Modern switches come with MDIX ports but the speed and duplex setting must remain on auto.

[Implement a small switched network]

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

Question 40: (QID=3694)

We need a minimum of 2500 hosts on each of the subnets. Our network address is 10.0.0.0/8. What is the subnet mask?

1. 255.255.224.0

2. 255.255.248.0

3. 255.255.240.0

4. 255.255.192.0

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

Correct answer(s): 3

Explanation: To provide 2500 hosts on each subnet we need 12 bits available for host addressing.

Following the rules: 2^12 – 2 = 4096 – 2 = 4094 possible hosts on each subnet. Now we have 12 bits available for the subnet mask or in binary 1111 1111.1111 1111.1111 0000. The first 8 bits are from the default subnet mask of the network, convert the previous into decimal and it gives us 255.255.240.0 or /20.

[Implement an IP addressing scheme and IP services to meet network requirements for a small branch office]

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

Question 41: (QID=2974)

We want to see a summary of the VLANs configured on our Catalyst 2960 switch. What command do we use?

1. Show vlan

2. Show vlan summary

3. Show vlan detail

4. Show vlan brief

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

Correct answer(s): 4

Explanation: The show vlan brief command displays one line for each of the VLANs configured on the switch. The line contains the VLAN name, status and port membership.

[Implement a small switched network]

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

Question 42: (QID=3695)

Given the following network 172.16.1.0/26. How many hosts do we have available on each of the subnets?

1. 62

2. 4096

3. 64

4. 128

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

Correct answer(s): 1

Explanation: /26 or 255.255.255.192 leaves us 6 bits for possible hosts on each subnet. Following the rule for hosts 2^n -2 = available hosts, 2^6 – 2 = 64 – 2 = 62 hosts. The -2 is to deduct the network address and the broadcast address of the subnet.

[Implement an IP addressing scheme and IP services to meet network requirements for a small branch office]

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

Question 43: (QID=1481)

We need 30 hosts on each of the subnets we create from the following network 192.168.3.0/24. What is the correct subnet mask?

1. 255.255.0.0

2. 255.255.255.0

3. 255.255.252.0

4. 255.255.255.224

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

Correct answer(s): 4

Explanation: We need 30 hosts on each subnet and in order to accommodate those we need 5 bits of the last octet to be allocated to hosts 2^5 -2 = 30. This leaves us 3 bits for the available subnets 2^3 = 8 subnets. In binary that becomes 111, first 3 bits for the subnet or 224 and the remaining 5 positions for the hosts on each subnet.

[Implement an IP addressing scheme and IP services to meet network requirements for a small branch office]

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

Question 44: (QID=1281)

RFC1918 specifies the allocation of IP Addresses for Private Internetworks. What are they?

1. 10.0.0.0 - 10.255.255.255

2. 192.168.0.0 - 192.168.255.255

3. 172.16.0.0 - 172.32.0.0

4. 172.16.0.0 – 172.31.255.255

5. 192.169.0.0 - 192.169.255.255

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

Correct answer(s): 1 2 4

Explanation: 10.0.0.0, 172.16.0.0 – 172.31.255.255 and 192.168.0.0 are the IP Address ranges that must be used in private internetworks. These address ranges are not routed on the internet. To find out more about this: RFC1918.

[Implement an IP addressing scheme and IP services to meet network requirements for a small branch office]

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

Question 45: (QID=25130)

When we have more than one AP in our infrastructure mode it is called?

1. BSS

2. ESS

3. CSS

4. EBSS

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

Correct answer(s): 2

Explanation: A extended service set or ESS is created when we use more than one AP with overlap in infrastructure mode.

[Explain and select the appropriate administrative tasks required for a WLAN]

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

Question 46: (QID=3614)

We notice a huge number of FCS errors on one of the switch ports that is running in full-duplex mode. What could be the cause of this?

1. Faulty switch port

2. Faulty cable

3. It is normal to have FCS errors in full-duplex mode

4. The switch is running out of memory

5. Software/hardware issues with the NIC

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

Correct answer(s): 1 2 5

Explanation: In full-duplex mode the collision counter is not active. If the FCS, CRC errors increment then the most likely cause is a duplex mismatch. Other causes can be a faulty cable, a faulty switch port or hardware/software issues with the NIC.

[Implement a small switched network]

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

Question 47: (QID=2970)

We have acquired a new Catalyst 3550 switch with Enhanced IOS image. What command allows us to remotely manage that switch using Cisco’s defaults?

A) Switch(config)#interface vlan1

Switch(config-if)#ip address 10.1.1.5 255.255.255.0

B) Switch(config)#interface fastethernet0/1

Switch(config-if)#ip address 10.1.1.5 255.255.255.0

C) Switch(config)#interface vlan1

Switch(config-vlan)#ip address 10.1.1.5 255.255.255.0

D) Switch(config)#interface ip 10.1.1.5 255.255.255.0

1. A

2. B

3. C

4. D

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

Correct answer(s): 1

Explanation: We assign an ip address to the default management VLAN 1 using interface configuration mode. By default the management VLAN is 1 but it can be any VLAN between 1 to 1001.

[Implement a small switched network]

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

Question 48: (QID=2369)

We want to try a new IOS release but we don’t have enough space on our Flash memory to hold both IOS’s. What needs to be done to use the new image?

1. Add the following line to the configuration: no boot system flash [filename]

2. Add the following line to the configuration: boot system tftp [filename] [ip address]

3. Add the following line to the configuration: no boot system rom

4. This can not be done; we need to upgrade the IOS

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

Correct answer(s): 2

Explanation: To specify the system image that the router loads at startup, use one of the following boot system global configuration commands. To remove the startup system image specification, use the no form of the command.

boot system file-url

no boot system file-url

boot system flash [flash-fs:][partition-number:][filename]

no boot system flash [flash-fs:][partition-number:][filename]

boot system mop filename [mac-address] [interface]

no boot system mop filename [mac-address] [interface]

boot system rom

no boot system rom

boot system {rcp | tftp | ftp} filename [ip-address]

no boot system {rcp | tftp | ftp} filename [ip-address]

no boot system

[Implement a small routed network]

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

Question 49: (QID=1478)

What is the maximum cable length for UTP cable?

1. 185m

2. 2000m

3. 100m

4. 500m

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

Correct answer(s): 3

Explanation: 10 BaseT & 100 BaseT 100m

10 Base2 185m

10 Base5 500m

10 BaseFL 2000m

[Describe the operation of data networks]

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

Question 50: (QID=25147)

Which ppp protocol is used to test the data link connection?

1. UDP

2. Q.931

3. NCP

4. LCP

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

Correct answer(s): 4

Explanation: LCP or Link Control Protocol is used in the PPP protocol suite to test the data link connection.

[Implement and verify WAN links]