CCNA Cram Ch.2

Place the following steps of the encapsulation process in the proper order. *Packets or datagrams are converted to frames for transmission on the local network. Hardware (Ethernet) addresses are used to uniquely identify hosts on a local network segment. *Segments are converted to packets or datagrams, and a logical address is placed in the header so each packet can be routed through an internetwork. *User information is converted to data for transmission on the network. *Frames are converted to bits, and a digital encoding and clocking scheme is used. *Data is converted to segments, and a reliable connection is set up between the transmitting and receiving hosts.

At a transmitting device, the data encapsulation method works like this: 1. User information is converted to data for transmission on the network. 2. Data is converted to segments, and a reliable connection is set up between the transmitting and receiving hosts. 3. Segments are converted to packets or datagrams, and a logical address is placed in the header so each packet can be routed through an internetwork. 4. Packets or datagrams are converted to frames for transmission on the local network. Hardware (Ethernet) addresses are used to uniquely identify hosts on a local network segment. 5. Frames are converted to bits, and a digital encoding and clocking scheme is used.

Which port numbers are used by well-known protocols that use connectionless transport? A. 25 B. 53 C. 20 D. 69 E. 161 F. 110

B. 53 (DNS) D. 69 (TFTP) E. 161 (SNMP)

The OSI layers 5, 6 and 7 have been amalgamated into which layer in the TCP/IP model? A. Data B. Application C. Transport D. Internetwork

B. Application

In the traditional three-layer hierarchical model, in which layer would you apply security policies? A. Access B. Distribution C. Core

B. Distribution

What is the function of the "FCS"? A. Allows the receiving devices to lock the incoming bit stream. B. Error detection C. Identifies the upper-layer protocol D. Identifies the transmitting device

B. FCS is a field at the end of the frame that's used to store the cyclic redundancy check (CRC) answer. The CRC is a mathematical algorithm that's based on the data in the frame and run when each frame is built. When a receiving host receives the frame and runs the CRC, the answer should be the same.

Which three of the following are physical layer components? A. Switch B. NIC C. RJ-45 connector D. Hub E. STP

B. NIC C. RJ-45 connector D. Hub

Which of the following is not one of the actions taken in the operation of CSMA/CD when a collision occurs? A. A jam signal informs all devices that a collision occurred. B. The collision invokes a random backoff algorithm on the systems involved in the collision. C. Each device on the Ethernet segment stops transmitting for a short time until its backoff timer expires. D. All hosts have equal priority to transmit after the timers have expired.

B. The collision will invoke a backoff algorithm on all systems, not just the ones involved in the collision.

Which are elements of PAR? Choose all that apply. A. Devices that collide must wait to retransmit. B. The source device starts a timer for each segment and will retransmit that segment if an acknowledgment is not received before the timer expires. C. Devices will broadcast for the hardware address of the receiver. D. Source devices keep a record of all segments sent and expect an acknowledgment for each one. E. The receiving device will drop frames that it cannot buffer. F. The receiving device will acknowledge receipt of a segment by sending an acknowledgment indicating the next segment it expects.

B. The source device starts a timer for each segment and will retransmit that segment if an acknowledgment is not received before the timer expires. D. Source devices keep a record of all segments sent and expect an acknowledgment for each one. F. The receiving device will acknowledge receipt of a segment by sending an acknowledgment indicating the next segment it expects.

Which of the following can be considered a typical access-layer connection? Choose all that apply: A. Frame-Relay B. WiFi C. Ethernet D. PPP leased line

B. WiFi C. Ethernet

What is the PDU for the Physica Layer (1)?

Bits

In an Ethernet network, under what two scenarios can devices transmit? (Choose two.) A. When they receive a special token B. When there is a carrier C. When they detect that no other devices are sending D. When the medium is idle E. When the server grants access

C, D. An Ethernet network is a shared environment, so all devices have the right to access the medium. If more than one device transmits simultaneously, the signals collide and cannot reach the destination. If a device detects another device is sending, it will wait for a specified amount of time before attempting to transmit.

Which answer correctly lists the OSI PDUs in order? A. Data, packet, frame, segment, bit B. Bit, data, packet, segment, frame C. Data, segment, packet, frame, bit D. Bit, frame, segment, packet, data

C. Data, segment, packet, frame, bit "Did Sally Pack For Bermuda?"

Which of the following are application layer protocols? Choose all that apply. A. Ethernet B. CDP C. FTP D. TFTP E. Telnet F. ARP G. ICMP H. ATM

C. FTP D. TFTP E. Telnet

A network interface port has collision detection and carrier sensing enabled on a shared twisted-pair network. From this statement, what is known about the network interface port? A. This is a 10 Mbps switch port. B. This is a 100 Mb/s switch port. C. This is an Ethernet port operating at half-duplex. D. This is an Ethernet port operating at full-duplex. E. This is a port on a network interface card in a PC.

C. Half-duplex Ethernet networking uses a protocol called Carrier Sense Multiple Access with Collision Detection (CSMA/CD), which helps devices share the bandwidth evenly while preventing two devices from transmitting simultaneously on the same network medium.

What are the TCP/IP model layer names in order? A. Data, transport, Internet, network interface B. Data, Internet, transport, network interface C. Network interface, Internet, transport, application D. Application, transport, network, network interface

C. Network interface, Internet, transport, application

Which layer of the TCP/IP model is responsible for interhost data movement and uses either connection-oriented or connectionless protocols? A. Network B. Internet C. Transport D. Network interface E. Application

C. Transport

The last six characters (24 bits) of a MAC address are called the:

Card serial number

What is 1000Base-T (IEEE 802.3ab)

Category 5, four-pair UTP wiring up to 100 meters long and up to 1 Gbps.

What does the "0x" mean in the number 0x6A?

Cisco likes to put 0x in front of characters so you know that they are a hex value. It doesn't have any other special meaning.

For each of the following situations, determine whether a straight-through, crossover, or rolled cable would be used. Host to host Host to switch or hub Router direct to host Switch to switch Router to switch or hub Hub to hub Hub to switch Host to a router console serial communication (COM) port

Crossover Straight-through Crossover Crossover Straight-through Crossover Crossover Rolled

What is the correct order of PDUs? A. Packet, bits, frame, data, segment B. Segment, data, frame, packet, bits C. Data, segment, frame, packet, bits D. Bits, frame, packet, segment, data E. Data, segment, packet, bits, frame

D. Bits, frame, packet, segment, data

What is the TCP/IP model equivalent of the OSI Layer 3? A. Application B. Presentation C. Network D. Internet E. Internetwork F. Data G. Session

D. Internet

Which transport layer protocol provides connection-oriented, reliable transport? A. TFTP B. UDP C. Ethernet D. TCP E. Secure Shell

D. TCP

Which protocol will allow you to test connectivity through Layer 7? A. ICMP B. ARP C. RIP D. Telnet

D. Telnet

Which part of a MAC address indicates whether the address is a locally or globally administered address? A. FCS B. I/G bit C. OUI D. U/L bit

D. When set to 0, this bit represents a globally administered address, as specified by the IEEE, but when it's a 1, it represents a locally governed and administered address.

When configuring a terminal emulation program, which of the following is an incorrect setting? A. Bit rate: 9600 C. Parity: None D. Flow control: None E. Data bits: 1

D. When you set up the connection, use these settings: Bits per sec: 9600 Data bits: 8 Parity: None Stop bits: 1 Flow control: None

What is DHCP and what does it do?

DHCP (Dynamic Host Configuration Protocol): Assigns IP, mask, and DNS server (plus a bunch of other stuff) to hosts.

What is DNS and what does it do?

DNS (Domain Naming System): Translates a website name (easy for people) to an IP address (easy for computers).

What is the PDU for the Application Layer (7)?

Data

What is the PDU for the Presentation Layer (6)?

Data

What is the PDU for the Session Layer (5)?

Data

What is attenuation?

Defined as the loss of signal strength as it travels the length of a cable and is measured in decibels (dB). A higher-quality cable will have a higher-rated category and lower attenuation.

The OSI model Layer 3 corresponds to which TCP/IP model layer? A. Network B. Intranet C. Transport D. Data E. Network interface F. Internet

F. Internet

What is the Frame Check Sequence (FCS)?

FCS is a field at the end of the frame that's used to store the cyclic redundancy check (CRC) answer. The CRC is a mathematical algorithm that's run when each frame is built based on the data in the frame. When a receiving host receives the frame and runs the CRC, the answer should be the same. If not, the frame is discarded, assuming errors have occurred.

What is FTP and what does it do?

FTP (File Transfer Protocol): Reliably sends/retrieves all file types.

What is the PDU for the Data Link Layer (2)?

Frame

What is IMAP and what does it do?

IMAP (Internet Message Access Protocol): Sends and retrieves email with additional features/functionality.

What layer does ICMP function on?

Layer 3

What layer does the IP protocol function on?

Layer 3

What layer is responsible for logical, hierarchical addressing and path determination?

Layer 3

What is NTP and what does it do?

NTP (Network Time Protocol): Synchronizes networked device clocks.

The first six characters (24 bits) of a MAC address are called the:

Organizationally Unique Identifier (OUI) or vendor code, and identify the company that made the card.

What is PAR and where is it involved?

PAR (positive acknowledgment and retransmission) and is part of The TCP three-way handshake.

What is POP3 and what does it do?

POP3 (Post Office Protocol 3): Retrieves email.

What is the PDU for the Network Layer (3)?

Packet

What is Telnet and what does it do?

Provides a remote terminal connection to manage devices to which you are not close enough to use a console cable.

What does the "RJ" stand for in RJ45?

Registered Jack

What is SMTP and what does it do?

SMTP (Simple Mail Transfer Protocol): Sends email.

What is SNMP and what does it do?

SNMP (Simple Network Management Protocol): Communicates status and allows control of networked devices.

What is the PDU for the Transport Layer (4)?

Segment

What is the PDU for each layer?

Some People Fear Birthdays. Segment Packet Frame Bit

What is TFTP and what does it do?

TFTP (Trivial File Transfer Protocol): Simple, lightweight file transfer.

What is the Destination Address (DA)?

The DA is used by receiving stations to determine whether an incoming packet is addressed to a particular node. The destination address can be an individual address or a broadcast or multicast MAC address.

What is the Source Address (SA)?

The SA is a 48-bit MAC address used to identify the transmitting device.

What is the Start Frame Delimiter (SFD)?

The SFD is 10101011, where the last pair of 1s allows the receiver to come into the alternating 1,0 pattern somewhere in the middle and still sync up to detect the beginning of the data.

True or false? Layer 3 provides hierarchical addressing.

True. Layer 3 IP addressing provides for hierarchical address assignment.

Encapsulating a frame within a different type of frame is called:

Tunneling

Name 5 application layer protocols:

► HTTP (Hypertext Transfer Protocol): Browses web pages. ► FTP (File Transfer Protocol): Reliably sends/retrieves all file types. ► SMTP (Simple Mail Transfer Protocol): Sends email. ► POP3 (Post Office Protocol 3): Retrieves email. ► IMAP (Internet Message Access Protocol): Sends and retrieves email with additional features/functionality.

Name 6 application layer protocols:

► NTP (Network Time Protocol): Synchronizes networked device clocks. ► SNMP (Simple Network Management Protocol): Communicates status and allows control of networked devices. ► TFTP (Trivial File Transfer Protocol): Simple, lightweight file transfer. ► DNS (Domain Naming System): Translates a website name (easy for people) to an IP address (easy for computers). ► DHCP (Dynamic Host Configuration Protocol): Assigns IP, mask, and DNS server (plus a bunch of other stuff) to hosts. ► Telnet: Provides a remote terminal connection to manage devices to which you are not close enough to use a console cable.

What is the port number for DNS?

"Don't Need Sillyness" 53

What are the port numbers for FTP?

"Free To Party" 20 & 21

What is the port number for HTTP?

"Hardly Trying To Party" 80

What is the port number for NNTP?

"No Need To Party" 119

What is the port number for POP?

"Pooped Out Partying" 110

What is the port number for SMTP?

"Still Managing To Party" 25

What is the port number for TFTP?

"Too F*cked To Party" 69

A straight through cable transmit on pins ___ & ___ and receives on pins ___ & ___

1 & 2 3 & 6

What are the 3 main elements of PAR?

1. The sender starts a timer when it sends a segment, and will retransmit that segment if the timer expires before an acknowledgment is received for that segment. 2. The sender keeps a record of all segments sent and expects an acknowledgment of each one. 3. The receiving device acknowledges the receipt of a segment by sending a segment back to the sender indicating the next sequence number it expects.

What is 10Base-T (IEEE 802.3)

10 Mbps using category 3 (UTP) wiring for runs up to 100 meters.

What is 100Base-TX (IEEE 802.3u)

100Base-TX, most commonly known as Fast Ethernet; up to 100 meters

How many characters are in a MAC address?

12

What is the port number for NTP?

123

What is the port number for SNMP?

161

What is the port number for Telnet?

23

What is the port number for HTTPS?

443

What are the port numbers for DHCP?

67 & 68

What are the layers of the TCP/IP Model?

A TIN

For what two purposes does the Ethernet protocol use physical addresses? (Choose two.) A. To uniquely identify devices at layer 2 B. To allow communication with devices on a different network C. To differentiate a layer 2 frame from a layer 3 packet D. To establish a priority system to determine which device gets to transmit first E. To allow communication between different devices on the same network F. To allow detection of a remote device when its physical address is unknown

A, E. Physical addresses or MAC addresses are used to identify devices at layer 2. MAC addresses are only used to communicate on the same network. To communicate on different network, we have to use layer 3 addresses (IP addresses).

__________on an Ethernet network is the retransmission delay that's enforced when a collision occurs. A. Backoff B. Carrier sense C. Forward delay D. Jamming

A. Backoff on an Ethernet network is the retransmission delay that's enforced when a collision occurs. When that happens, a host will only resume transmission after the forced time delay has expired. Keep in mind that after the backoff has elapsed, all stations have equal priority to transmit data.

Which protocols use TCP? Choose all that apply. A. DNS B. SNMP C. SMTP D. FTP E. TFTP F. POP3

A. DNS (uses both TCP and UDP) C. SMTP D. FTP

The OSI model is useful when troubleshooting. Which of the following are true when troubleshooting using the OSI model as a reference? A. If you can consistently ping the host, the cable is probably not faulty. B. If pings fail three out of four times, the cable is definitely faulty. C. If you can consistently ping a host on a remote network, Layer 3 is functioning. D. If you could telnet to the host this morning but now you can't, it is certain that the problem is at Layer 7. E. If you can access the web-based interface of the server, but cannot ping it, the problem is definitely at Layer 3.

A. If you can consistently ping the host, the cable is probably not faulty. C. If you can consistently ping a host on a remote network, Layer 3 is functioning

Which of the following does TCP use to provide reliability? Choose all that apply. A. Sliding window B. IP addressing C. Secret numbers D. Acknowledgments E. Three-way handshake F. Sequence numbers

A. Sliding window D. Acknowledgments E. Three-way handshake F. Sequence numbers

True or false: Packets contain segments. A. True B. False

A. True Packet is the term used to describe the encapsulation performed at Layer 3

What is ARP and what layer does it function?

ARP. Address Resolution Protocol. ARP learns what MAC address is associated with a given IP address.

What is the Preamble of an ethernet frame?

An alternating 1,0 pattern provides a 5 MHz clock at the start of each packet, which allows the receiving devices to lock the incoming bit stream.