ICND1

Question 1

Which of the following protocols are examples of TCP/IP transport layer protocols?
A.  Ethernet
B.  HTTP
C.  IP
D.  UDP
E.  SMTP
F.  TCP

Answer 1

UDP and TCP

Question 2

Which of the following protocols are examples of TCP/IP data link layer protocols?
A.  Ethernet
B.  HTTP
C.  IP
D.  UDP
E.  SMTP
F.  TCP
G.  PPP

Answer 2

Ethernet and PPP

Question 3

The process of HTTP asking TCP to send some data and making sure that it is received correctly is an example of what?
A.  Same-layer interaction
B.  Adjacent-layer interaction
C.  OSI model
D.  All of these answers are correct.

Answer 3

Adjacent-layer interaction

Question 4

The process of TCP on one computer marking a TCP segment as segment 1, and the receiving computer then acknowledging the receipt of TCP segment 1 is an example of what?
A. Data encapsulation
B. Same-layer interaction
C. Adjacent-layer interaction
D. OSI model
E. All of the above answers are correct.

Answer 4

Same-layer interaction

Question 5

The process of a web server adding a TCP header to the contents of a web page, followed by adding an IP header and then adding a data link header and trailer, is an example of what?
A. Data Encapsulation
B. Same-layer interaction
C. OSI model
D. All of the above answers are correct.

Answer 5

Data Encapsulation

Question 6

Which of the following terms is used specifically to identify the entity created when encapsulating data inside data link layer headers or trailers?
A.  Data
B  Chunk
C.  Segment
D.  Frame
E.  Packet

Answer 6

Frame

Question 7

Which OSI layer defines the functions of logical network-wide addressing and routing?
A.  Layer 1
B.  Layer 2
C.  Layer 3
D.  Layer 4
E.  Layer 5. 6.or 7

Answer 7

Layer 3

Question 8

Which OSI layer defines the standards for cabling and connections?
A.  Layer 1
B,  Layer 2
C.  Layer 3
D.  Layer 4
E.  Layer 5, 6, or 7

Answer 8

Layer 1

Question 9

In the LAN for a small office, some user devices connect to the LAN using a cable, while others connect using wireless technology (and no cable). Which of the following is true regarding the use of Ethernet in this LAN?
A. Only the devices that use cables are using Ethernet.
B. Only the devices that use wireless are using Ethernet.
C. Both the devices using cables and those using wireless are using Ethernet.
D. None of the devices are using Ethernet.

Answer 9

Only the devices that use cables are using Ethernet.

Question 10

Which of the following Ethernet standards defines Gigabit Ethernet over UTP cabling?
A. 10GBASE-T
B. 100BASE-T
C. 1000BASE-T
D. None of the other answers is correct.

Answer 10

1000BASE-T

Question 11

Which of the following is true about Ethernet crossover cables for Fast Ethernet?
A. Pins 1 and 2 are reversed on the other end of the cable.
B. Pins 1 and 2 on one end of the cable connect to pins 3 and 6 on the other end of the cable.
C. Pins 1 and 2 on one end of the cable connect to pins 3 and 4 on the other end of the cable.
D. The cable can be up to 1000 meters long to cross over between buildings.
E. None of the other answers is correct.

Answer 11

Pins 1 and 2 on one end of the cable connect to pins 3 and 6 on the other end of the cable.

Question 12

Each answer lists two types of devices used in a 100BASE-T network. if these devices were connected with UTP Ethernet cables, which pairs of devices would require a straight-through cable? (Choose three answers)
A. PC and router
B. PC and switch
C. Hub and switch
D. Router and hub
E. Wireless access point (Ethernet port) and switch

Answer 12

PC and switch

                           Router and hub

     Wireless access point (Ethernet port) and switch

Question 13

Which of the following is true about the CSMA/CD algorithm?
A. The algorithm never allows collisions to occur.
B. Collisions can happen, but the algorithm defines how the computers should notice a collision and how to recover.
C. The algorithim works with only two devices on the same Ethernet.
D. None of the other answers is correct.

Answer 13

Collisions can happen, but the algorithm defines how the computers cshould notice a collision and how to recover.

Question 14

Which of the following is true about the Ethernet FCS field?
A. Ethernet uses FCS for error recovery.
B. It is 2 bytes long.
C. It resides in the Ethernet trailer, not in the Ethernet header.
D. It is used for encryption.

Answer 14

It resides in the Ethernet trailer, not in the Ethernet header.

Question 15

Which of the following are true about the format of Ethernet addresses(Choose three answers)
A. Each manufacturer puts a unique OUI code into the first 2 bytes of the address.
B. Each manufacturer puts a unique OUI code into the first 3 bytes of the address.
C. Each manufacturer puts a unique OUI code into the first half of the address.
D. The part of the address that holds this manufacturer’s code is called the MAC.
E. The part of the address that holds this manufacturer’s code is called the OUI.
F. The part of the address that holds this manufacturer’s code has no specific name.

Answer 15

Each manifacturer puts a unique OUI code into the firt 3 bytes of the address.

Each manufacturer puts a unique OUI code into the first half of the address.

The part of the address that holds this manufacturer’s code is called the OUI.

Question 16

Which of the following terms describe Ethernet addresses that can be used to send one frame that is delivered to multiple devices on the LAN?  (Choose two answers).
A.  Burned-in address
B.  Unicast address
C.  Broadcast address
D.  Multicast address

Answer 16

Broadcast address

                        Multicast address

Question 17

Which of the following protocols are examples of TCP/IP transport layer protocols?
A.	Ethernet
B.	HTTP
C.	IP
D.	UDP
E.	SMTP
F.	TCP

Answer 17

UDP and TCP.

Of the remaining answers, Ethernet defines both physical and data link protocols, PPP is a data link protocol, IP is a network layer protocol, and SMTP and HTTP are application layer protocols

Question 18

The process of TCP on one computer marking a TCP segment as segment 1, and the receiving computer then acknowledging the receipt of TCP segment 1 is an example of what?
A.	 Data encapsulation
B.	Same-layer interaction
C.	Adjacent-layer interaction
D.	OSI model
E.	All of these answers are correct

Answer 18

B. Same-layer interaction occurs on multiple computers. The functions defined by that layer typically need to be accomplished by multiple computers—for example, the sender setting a sequence number for a segment and the receiver acknowledging receipt of that segment. A single layer defines that process, but the implementation of that layer on multiple devices is required to accomplish the function.

Question 19

The process of a web server adding a TCP header to the contents of a web page, followed by adding an IP header and then adding a data link header and trailer, is an example of what?
A.	Data encapsulation
B.	Same-layer interaction
C.	OSI model
D.	All of the above answers are correct

Answer 19

A. Encapsulation is defined as the process of adding a header in front of data supplied by a higher layer (and possibly adding a trailer as well).

Question 20

Which of the following terms is used specifically to identify the entity created when encapsulating data inside data link layer headers and trailers?
A.	Data
B.	Chunk
C.	Segment
D.	Frame
E.	Packet

Answer 20

D. By convention, the term frame refers to the part of a network message that includes the data link header and trailer, with encapsulated data. The term packet omits the data link header and trailer, leaving the network layer header with its encapsulated data. The term segment omits the network layer header, leaving the transport layer header and its encapsulated data

Question 21

Which of the following is true about the Ethernet FCS field?
A. Ethernet uses FCS for error recovery
B. It is 2 bytes long
C. It resides in the Ethernet trailer, not the Ethernet header.
D. It is used for encryption.

Answer 21

C. The 4-byte Ethernet FCS field, found in the Ethernet trailer, allows the receiving node to see what the sending node computed with a math formula that is a key part of the error-detection process. Note that Ethernet defines the process of detecting errors (error detection), but not error recovery

Question 22

In the cabling for a leased line, which of the following typically connects to a four-wire line provided by a telco?
A. Router serial interface without internal CSU/DSU.
B. CSU/DSU
C. Router serial interface with internal transceiver
D. Switch serial interface.

Answer 22

B. The four-wire circuit cable supplied by the telco connects to the device acting as the CSU/DSU. That can be an external CSU/DSU or a CSU/DSU integrated into a router serial interface card. LAN switches do not have serial interfaces, and router serial interfaces do not have transceivers

Question 23

Which of the following is an accurate speed at which a leased line can operate in the United States?
A.	100 Mbps
B.	100 Kbps
C.	256 Kbps
D.	6.4 Mbps

Answer 23

C. Leased lines can run at various preset speeds. These include multiples of 64 kbps, up through 24 times 64 kbps. The speeds can also be multiples of T1 speed (1.544 Mbps), up to 28 times that speed.

Question 24

Which of the following fields in the HDLC header used by Cisco routers does Cisco add, beyond the ISO standard HDLC?
A.	Flag
B.	Type
C.	Address
D.	FCS

Answer 24

B. The standard HDLC header does not include a Type field, which identifies the type of packet encapsulated inside the HDLC frame.

Question 25

Two routers, R1 and R2, connect using an Ethernet over MPLS service. The service provides point-to-point service between these two routers only, as a Layer 2 Ethernet service. Which of the following are the most likely to be true about the WAN? (Choose two answers) A. R1 will connect to a physical Ethernet link, with the other end of the cable connected to R2. B. R1 will connect to a physical Ethernet link, with the other end of the cable connected to a device at the WAN service provider point of presence. C. R1 will forward data-link frames to R2 using an HDLC header/trailer. D. R1 will forward data-link frames to R2 using an Ethernet header/trailer.

Answer 25

B and D. The physical installation uses a model in which each router uses a physical Ethernet link to connect to some SP device in an SP facility called a point of presence (PoP). The Ethernet link does not span from each customer device to the other. From a data-link perspective, both routers use the same Ethernet standard header and trailer used on LANs; HDLC does not matter on these Ethernet WAN links

Question 26

``` Which of the following internet access technologies, used to connect a site to an ISP, offers asymmetric speeds? (Choose two answers) A. Leased lines B. DSL C. Cable internet D. BGP ```

Answer 26

B and C. Leased lines transmit data at the same speed in both directions, making them a symmetric service. DSL and cable Internet offer asymmetric speeds, with a faster downstream speed. BGP is a routing protocol and not an Internet access technology.

Question 27

Fred has just added DSL service at his home, with a separate DSL modem and consumer-grade router with four Ethernet ports. Fred wants to use the same old phone he was using before the installation of DSL. Which is most likely true about the phone cabling and phone used with his new DSL installations? A. He uses the old phone, cabled to one of the router/switch device’s Ethernet ports. B. He uses the old phone, cabled to the DSL modem’s ports. C. He uses the old phone, cabled to an existing telephone port and not to any new device. D. The old phone must be replaced with a digital phone.

Answer 27

C. With DSL, the requirements on the phone’s wiring are unchanged. The phone can connect to any working telephone jack, as if the DSL modem and router did not exist.

Question 28

``` Which of the following are functions of OSI Layer 3 protocols? (Choose two answers) A. Logical addressing B. Physical addressing C. Path selection D. Arbitration E. Error recovery ```

Answer 28

A and C. The network layer defines logical addressing, in contrast to physical addressing. The logical address structure allows easy grouping of addresses, which makes routing more efficient. Path selection refers to the process of choosing the best routes to use in the network. Physical addressing and arbitration typically are data link layer functions, and error recovery typically is a transport layer function.

Question 29

``` Which of the following is a valid Class C IP address that can be assigned to a host? A. 1.1.1.1 B. 200.1.1.1 C. 128.128.128.128 D. 224.1.1.1 ```

Answer 29

B. 224.1.1.1 is a Class D address

Question 30

``` What is the assignable range of values for the first octet for Class A IP networks? A. 0 to 127 B. 0 to 126 C. 1 to 127 D. 1 to 126 E. 128 to 191 F. 128 to 192 ```

Answer 30

D.The first octet of Class A addresses ranges from 1 to 126, inclusive; Class B, 128 to 191, inclusive; and Class C, 192 to 223 inclusive. 127 is technically in the Class A range, but it is a reserved address used as a loopback.

Question 31

``` PC1 and PC2 are on two different Ethernet LANs that are separated by an IP router. PC1’s IP address is 10.1.1.1, and no subnetting is used. Which of the following addresses could be used for PC2? (Choose two answers) A. 10.1.1.2 B. 10.2.2.2 C. 10.200.200.1 D. 9.1.1.1 E. 225.1.1.1 F. 1.1.1.1 ```

Answer 31

D and F. Without any subnetting in use, all addresses in the same network as 10.1.1.1—all addresses in Class A network 10.0.0.0—must be on the same LAN. Addresses separated from that network by some router cannot be in network 10.0.0.0. So, the two correct answers are the only two answers that list a valid unicast IP address that is not in network 10.0.0.0.

Question 32

Imagine a network with two routers that are connected with a point-to-point HDLC serial link. Each router has an Ethernet, with PC1 sharing the Ethernet with Router 1 and PC2 sharing the Ethernet with Router 2. When PC1 sends data to PC2, which of the following it true? A. Router1 strips the Ethernet header and trailer off the frame received from PC1, never to be used again. B. Router1 encapsulate the Ethernet frame inside an HDLC header and send the frame to Router2, which extracts the Ethernet frame for forwarding to PC2. C. Router1 strips the Ethernet header and trailer off the frame received from PC1, which is exactly re-created by Router2 before forwarding date to PC2. D. Router1 removes the Ethernet, IP, and TCP headers and rebuilds the appropriate headers before forwarding the packet to Router2.

Answer 32

A. PC1 will send an Ethernet frame to Router 1, with PC1’s MAC address as the source address and Router 1’s MAC address as the destination address. Router 1 will remove the encapsulated IP packet from that Ethernet frame, discarding the frame header and trailer. Router 1 will forward the IP packet by first encapsulating it inside an HDLC frame, but Router 1 will not encapsulate the Ethernet frame in the HDLC frame but rather the IP packet. Router 2 will de-encapsulate the IP packet from the HDLC frame and forward it onto the Ethernet LAN, adding a new Ethernet header and trailer, but this header will differ. It will list Router 2’s MAC address as the source address and PC2’s MAC address as the destination address

Question 33

``` Which of the following does a router normally use when making a decision about routing TCP/IP packets? A. Destination MAC address B. Source MAC address. C. Destination IP address. D. Source IP address. E. Destination MAC and IP addresses. ```

Answer 33

C. Routers compare the packet’s destination IP address to the router’s IP routing table, making a match and using the forwarding instructions in the matched route to forward the IP packet.

Question 34

``` Which of the following are true about a LAN-connected TCP/IP host and its IP routing (forwarding) choices? (Choose two answers) A. The host always sends packets to its default gateway. B. The host sends packets to its default gateway if the destination IP address is in a different class of IP network than the host. C. The host sends packets to its default gateway if the destination IP address is in a different subnet than the host. D. The host sends packets to its default gateway if the destination IP address is in the same subnet as the host. ```

Answer 34

B and C. IPv4 hosts generally use basic two-branch logic. To send an IP packet to another host on the same IP network or subnet that is on the same LAN, the sender sends the IP packet directly to that host. Otherwise, the sender sends the packet to its default router (also called the default gateway).

Question 35

Which of the following are functions of a routing protocol? (Choose two answers) A. Advertising known routes to neighboring routers. B. Learning routes for subnets directly connected to the router. C. Learning routes, and putting those routes into the routing table, for routes advertised to the router by its neighboring routers. D. Forwarding IP packets based on a packet’s destination IP address.

Answer 35

A and C. Routers do all the actions listed in all four answers; however, the routing protocol does the functions in the two listed answers. Independent of the routing protocol, a router learns routes for IP subnets and IP networks directly connected to its interfaces. Routers also forward (route) IP packets, but that process is called IP routing, or IP forwarding, and is an independent process compared to the work of a routing protocol.

Question 36

``` A company implements a TC/IP network, with PC1 sitting on an Ethernet LAN. Which of the following protocols and features requires PC1 to learn information from some other server device? A. ARP B. Ping C. DNS D. None of the above is correct. ```

Answer 36

C. Address Resolution Protocol (ARP) does allow PC1 to learn information, but the information is not stored on a server. The ping command does let the user at PC1 learn whether packets can flow in the network, but it again does not use a server. With the Domain Name System (DNS), PC1 acts as a DNS client, relying on a DNS server to respond with information about the IP addresses that match a given hostname.

Question 37

``` Which of the following header fields identify which TCP/IP application gets data received by the computer? (Choose two answers) A. Ethernet Type B. SNAP Protocol Type C. IP Protocol D. TCP Port Number E. UDP Port Number ```

Answer 37

D and E. Many headers include a field that identifies the next header that follows inside a message. Ethernet uses the Ethernet Type field, and the IP header uses the Protocol field. The TCP and UDP headers identify the application that should receive the data that follows the TCP or UDP header by using the port number field in the TCP and UDP headers, respectively

Question 38

``` Which of the following are typical functions of TCP? (Choose four answers) A. Flow control (windowing) B. Error recovery C. Multiplexing using port numbers D. Routing E. Encryption F. Ordered data transfer ```

Answer 38

A, B, C, and F. IP, not TCP, defines routing. Many other protocols define encryption, but TCP does not. The correct answers simply list various TCP features.

Question 39

``` Which of the following functions is performed by both TCP and UDP? A. Windowing B. Error recovery C. Multiplexing using port numbers D. Routing E. Encryption F. Ordered data transfer ```

Answer 39

C. TCP, not UDP, performs windowing, error recovery, and ordered data transfer. Neither performs routing or encryption.

Question 40

``` What do you call data that includes the Layer 4 protocol header, and data given to Layer 4 by the upper layers, not including any headers and trailers from Layers 1 to 3? (Choose two answers) A. L3PDU B. Chunk C. Segment D. Packet E. Frame F. L4PDU ```

Answer 40

C and F. The terms packet and L3PDU refer to the header plus data encapsulated by Layer 3. Frame and L2PDU refer to the header (and trailer), plus the data encapsulated by Layer 2. Segment and L4PDU refer to the header and data encapsulated by the transport layer protocol

Question 41

In the URL http://www.certsills.com/ICND1, which part identifies the web server? A. http B. www.certskills.com C. Certskills.com D. http://www.certskills.com E. The file name.html includes the hostname.

Answer 41

B. Note that the hostname is all the text between the // and the /. The text before the // identifies the application layer protocol, and the text after the / represents the name of the web page.

Question 42

Fred opens a web browser and connects to the www.certskills.com website. Which of the following are typically true about what happens between Fred’s web browser and the web server? (Choose two answers) A. Messages flowing toward the server use UDP destination port 80. B. Messages flowing from the server typically use RTP. C. Messages flowing to the client typically use a source TCP port number of 80. D. Messages flowing to the server typically use TCP.

Answer 42

C and D. Web traffic uses TCP as the transport protocol, with HTTP as the application protocol. As a result, the web server typically uses well-known TCP port 80, which is the well-known port for HTTP traffic. Messages flowing to the web server would have a destination TCP port of 80, and messages flowing from the server would have a source TCP port of 80.