Tuesday, June 3, 2008

CISCO SEMESER 1: MODULE 6

1 What happens on an Ethernet network after a collision occurs? (Choose three.)

* A backoff algorithm is invoked and transmission is stopped.
Devices involved in the collision have a random period of time for priority retransmission of the damaged packet.
The devices involved in the collision release a token indicating the time each station may begin retransmitting.
* The devices involved in the collision do not have priority to transmit data.
* The devices with data to transmit return to a listen-before-transmit mode.
Transmit work will restart with the reissuance of all data.

2 Which of the following are the functions of CSMA/CD? (Choose three.)

* transmitting and receiving data packets
releasing a token when the network is clear
* detecting errors within data packets or on the network
passing a token to each station on the network
* decoding data packets and checking them for valid addresses before passing them to the upper layers of the OSI model

3 Which of the following is included in the frame address field? (Choose two.)

source IP address
destination IP address
destination subnet mask
* source MAC address
* destination MAC address

4 Which options below are field names of a generic frame? (Choose three.)

IP header
voltage reference
* data
description
* length
* frame check sequence

5 Ethernet standard specifications limit network service interruption. Select the items that describe the standards. (Choose three.)

minimum segment length
* maximum segment length
minimum number of stations per segment
* maximum number of stations per segment
minimum number of repeaters between segments
* maximum number of repeaters between segments

6 Which characteristics of Ethernet contribute to its widespread use? (Choose three.)

* ease of maintenance
collision free technology
* scalability
* low cost of installation
compatibility with 802.5 standard
collision avoidance capabilities

7 What does the word "Base" indicate in 10Base2?

The number standard used.
* Baseband signaling is used.
Only a portion of the transmission medium is used.
Broadband signaling is used.

8 Where does the MAC address originate?

DHCP server database
configured by the administrator
* burned into ROM on the NIC card
network configuration on the computer
included in the creation of the processor chip

9 What is the length of a MAC address?

8 bits
8 bytes
24 bits
24 bytes
* 48 bits
48 bytes

10 Which statements below are true about Ethernet? (Choose three.)

addresses the needs of Layer 2 and Layer 3 of the OSI model
first released as a Xerox proprietary standard
* essentially the same as 802.3 standards
* bandwidth can be increased without changing the underlying technology
essentially the same as 802.2 standards
* original idea developed at the University of Hawaii

11 How is a MAC address represented?

four groups of eight binary digits separated by a decimal point
four Base10 digits separated by a decimal point
six hexadecimal digits
* twelve hexadecimal digits
twenty-four Base10 digits

12 Which features describe the concept of Carrier Sense Multiple Access with Collision Detection? (Choose two.)

collisionless environment
* non-deterministic
deterministic
* uses first-come, first-served approach
uses a token to transmit data

13 What is the name of the Layer 2 Protocol Data Unit(PDU)?

packet
* frame
bit
data
segment

14 After an Ethernet collision, when the backoff algorithm is invoked, which device has priority to transmit data?

the device involved in the collision with the lowest MAC address
the device involved in the collision with the lowest IP address
* any device in the collision domain whose backoff timer expires first
those that began transmitting at the same time

15 Which of the following are features of a Token Ring network? (Choose two.)

* collisionless environment
non-deterministic
* deterministic
uses CSMA/CD
prone to collisions

16 In which two layers of the OSI model does Ethernet function? (Choose two.)

application
session
transport
network
* data link
* physical

17 Which of the following are specified by IEEE standards as sublayers of the OSI data link layer? (Choose two.)

* Logical Link Control
Logical Layer Control
* Media Access Control
Logical Link Communication
Media Access Communication
Physical Access Communication

18 Which ports on a hub forward traffic?

only to the port where the destination host resides
to the ports in all other collision domains
* all ports except the originating port
all ports

19 Which of the following statements about full-duplex Ethernet operation are true? (Choose two.)

Full duplex is supported on shared media.
In full duplex, only one station may transmit at a time.
* Full duplex is preferred over half duplex in link establishment negotiation.
All implementations of Ethernet can support both half duplex and full duplex.
* Two methods of achieving a full duplex are auto-negotiation and administrative configuration.

20 How do Ethernet stations respond to collisions on the network? (Choose three.)

* After the collison is detected by all stations, a backoff algorithm is implemented.
* Each station continues transmitting for a short while after a collison is detected.
All stations that were involved in the collision will negotiate priority transmission status for use after the delay period.
* When a workstation delay period expires, it will attempt to gain access to the networking media
The delay period is the same length for every collision.

21 How are collisions detected on an Ethernet network?

Stations identify the altered FCS field on the colliding packets.
* The signal amplitude on the networking media is higher than normal.
Traffic on the network cannot be detected due to a blockage
The signal amplitude on the networking media is lower than normal.

22 What is the purpose of the preamble in an Ethernet frame?

is used as a pad for data
identifies the source address
identifies the destination address
marks the end of timing information
* is used for timing synchronization with alternating patterns of ones and zeros

23 Which of the following describe Ethernet MAC addresses? (Choose three.)

* 24 bit OUI and 24 bit serial number
32 bit network and 48 bit host address
* 6 pairs of hex digits
48 hex digits
logical host address
* physical address

24 Which IEEE standard defines a token ring network?

802.1
802.3
* 802.5
802.11b
802.11g


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