my CS

Which OSI layer handles the concept of logical addressing?

Network

Routers operate at which of the following of the OSI Model: name and layer#

Network Layer & Layer 3

What OSI layer deals with logical addressing between networks?

Network layer

What layer of the OSI model does not add a header to the data payload?

Physical The Physical layer is the only layer that does not add a header to the data.

What OSI layer transmits bits from one device to another and modulates the transmission stream over a medium?

Physical Layer

True or False: Fragmentation is the process of dividing the contents of large messages into smaller packets for delivery over an internetwork.

True

What are the two types of copper cable?

Twisted pair and Coax

Which of these would perform encapsulation?

Sending node

What layer would you find the TCP and UDP protocols?

Layer 4

Describe a 100BASE-TX cable.

100 Mbps, baseband signaling, twisted pair cable

The Maximum Transmission Unit (MTU) is usually __________ bytes.

1500

Which wireless frequency band suffers the most from co-channel interference?

2.4 GHz

How many collision domains exist if there is one hub plugged into a four-port bridge?

4

If a medium allows frequencies from 5000 MHz and 5050 MHz, what would be considered the channel's bandwidth?

50 MHz

Which are the top two layers of the OSI model (layers 6 and 7)?

7) Application 6) Presentation

What component is responsible for translating the computer's digital signals into electrical or optical signals that travel on network cable?

A transceiver

Which protocol assigns an IP address to a MAC address?

ARP Address Resolution Protocol

At which OSI layer do programs access network services?

Application The Application layer is the top layer that approaches protocols for application interaction with the network.

_________ occur when two (or more) nodes try to communicate at once.

Collisions

Consider the features of Protocol Data Units (PDUs) and determine what role encapsulation performs during communications.

Describes how data should be packaged

Consider the features of Protocol Data Units (PDUs) and determine what role encapsulation performs during communications.

Describes how data should be packaged. Encapsulation describes how data should be packaged for transmission. The basic process of encapsulation is for the protocol to add fields in a header to whatever data (payload) it receives from an application or other protocol.

True or false: the Session layer is responsible for passing data to the Network layer at the lower bound and the Presentation layer at the upper bound.

False=The Session layer is between the Transport and Presentation layers.

A network comprised of four hosts and centralized networking devices is having an issue where all traffic is replicated to each other end device. Due to this configuration, the chance of collision is very high. What networking device is most likely being used?

Hub

Which of the following devices does not resides at the data link layer of the OSI model? Switch Hub, switches

Hub

Which of the following reside at the physical layer of the OSI model? (Select 2 answers)

Hub & Cabling

What layer would you find the TCP and UDP protocols?

Layer 4- Transport

Layer 1 of the TCP/IP model is also known as the:

Link/Network Interface Layer

To which layer of the OSI model does the TCP/IP model Internet layer correspond?

Network layer (layer 3)

What OSI layer deals with logical addressing between networks?

Network layer Layer 3

What does digital signaling use to create the highs and lows of digital waveforms?

The 1's and 0's of the binary

Summarize the functions of the Link layer in the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol stack.

The Application layer is the layer at which many Transmission Control Protocol/Internet Protocol (TCP/IP) services (high level protocols) can be run, such as File Transfer Protocol (FTP).

Compare the Open System Interconnection (OSI) model and the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol stack and determine which statements accurately distinguish between the two. (Select two).

The Application layer of TCP/IP consolidates Layers 5-7 of the OSI model. PPP, PPTP, and L2TP occur at the Link layer of the TCP/IP protocol stack and occur at Layer 2 of the OSI model.

If a packet is addressed to a remote network, what destination MAC address will the sending node use?

The MAC address of the default gateway.

At which OSI layer is the concept of a port number introduced?

Transport

Which OSI layer is responsible for establishing reliable connections between two devices?

Transport Layer

Which OSI layer is responsible for identifying application data via port numbers?

Transport layer

Which TCP/IP model layer might also be described as the Host-to-Host layer?

Transport layer (layer 4)

If you connect two hubs with a crossover cable, are nodes connected to either hub in the same collision domain?

Yes

Power over Ethernet (PoE)

supplying electrical power from a switch port over ordinary data cabling to a connected powered device, such as a VoIP handset or wireless access point. PoE is defined in two IEEE standards (now both rolled into 802.3-2018)

What is fragmentation?

Dividing the contents of large messages into smaller packets for delivery over an internetwork. Dividing the message into fragments allows for a single packet to be resent at relatively little cost if it is lost or damaged during transmission.

Match each type of traffic to the correct mapping. Unicast traffic Multicast traffic Broadcast traffic

Unicast- one-to-one Multicast traffic one-to-many Broadcast traffic one-to-all

At which OSI layer do programs on a network node access network services?

Application Layer

The TCP/IP model condenses which of the following OSI layers to create the Application layer? (Choose 3)

Application Presentation Session The first layer of the TCP/IP model (Link/Network Interface) combines the Physical and Data Link layers of the OSI model. The second layer (Internet) lines up with the Network layer. The third layer (Transport) lines up with the Transport layer. The fourth layer (Application) combines the Session, Presentation, and Application layers.

If a mapping for a local destination host is not found in a source host ARP cache, how does the source host send an ARP request?

As a broadcast to all local hosts.

If a network administrator is measuring the loss of signal strength, what are they trying to find?

Attenuation

A component of Fast Ethernet that allows devices to choose the highest supported connection parameters is ____________.

Autonegotiation

What is the name of the protocol data unit (PDU) used at the OSI physical layer?

Bit

What is the data unit used at the OSI physical layer?

Bit Bits are used at the Physical layer. Frames are used at the Data Link layer. Packets are used at the Network layer. Segments are used at the Transport Layer.

Devices can only transmit on an Ethernet network when the media is clear, and the opportunity to transmit becomes less frequent as more devices are added. Also, the probability of collisions increases. These problems can be overcome by installing a hub.

False- The description of the problem is true, but the solution is not. This issue is resolved by using a bridge or (more likely these days) a switch.

What does a switch use in order to segment collision domains and determine where frames should be sent?

MAC Address Table

The TCP/IP Model's Application layer matches up with which 3 OSI Model layers?

Session, Presentation, Application

Which of the following would be considered a valid MAC address?

00 : 0a : 87 : 5e : 44 : 2c

Powered devices can draw up to about 25 W, with a maximum current of 600 mA. Various proprietary schemes were used prior to the ratification of 802.3at.

802.3at (PoE+)

Differentiate between the characteristics of a Local Area Network (LAN) and a Wide Area Network (WAN).

A LAN is a network with one geographic location while a WAN is spread across multiple geographic locations with shared links.

A WAN describes which of the following network topologies?

A network that spans more than one geographical location. A WAN must be spread over multiple geographical locations. The number of devices doesn't matter.

True or false: MAC addresses are used in logical addressing and can be found at layer 3 of the OSI Model.

False

True or false: A bridge does not forward broadcast or multicast traffic.

False Segments on different bridge ports are in separate collision domains but the same broadcast domain.

The number of symbols that can be sent per second is called a

Baud rate

__________ media involves using wires and cables, while __________ media uses microwave radio frequencies to connect media.

Bounded; unbounded

Which of the following devices are part of Layer 2 of the OSI model? (Select two)

Bridge & Network Interface Card Modems, hubs, transceivers, and repeaters are all examples of devices used at the Physical layer. NIC Cards, Bridges, Switches and Wireless Access Points (WAPs) are examples of Data Link layer devices.

In the OSI model, physical addressing takes place at the:

Data Link layer

Which OSI layer packages bits of data from the Physical layer into frames?

Data link

Which of the following protocols resides at the Application layer of the OSI model?

HTTP Application-layer protocols provide an interface for software programs on network hosts that have established a communications channel through the lower-level protocols to exchange data. Besides HTTP(S), other examples of protocols are SMTP, POP, IMAP, and FTP (used for web, email, and file transfer). TCP/UDP are Transport-layer protocols. IP is a Network-layer protocol.

What is the purpose of Layer 4 of the OSI model?

It regulates data transfer using TCP or UDP. One of the critical functions of the Transport layer is to identify each type of network application by assigning it a TCP/UDP port number. For example, data from the HTTP web browsing application can be identified as port 80, while data from an email server can be identified as port 25.

You have received a help request from a user who believes there is something wrong with their NIC - what OSI layer would this concerning?

Layer 2

Evaluate the roles of Layer 1 and Layer 2 of the Open Systems Interconnection (OSI) model. Which of the following devices are part of Layer 2? (Select two)

Layer 2 is the Data Link layer. This layer is responsible for transferring data between nodes on the same logical segment. A bridge joins two network segments while minimizing the performance reduction. A Network Interface Card (NIC) joins a host to network media and enables it to communicate over the network by assembling and disassembling frames.

At which layer of the OSI model does IP addressing take place?

Layer 3 At the Network layer (layer 3), the Internet Protocol (IP) provides logical host and network addressing and routing. IP provides best-effort delivery of an unreliable and connectionless nature. Delivery is not guaranteed, and a packet might be lost, delivered out of sequence, duplicated, or delayed.

Importance of the content of packets and port numbers comes in at what OSI model layer?

Layer 4

What is the name of the protocol data unit used at the OSI network layer?

Packet

Your coworker suspects there are some networking cabling issues in their office space. What layer of the OSI model would you use to describe the probable location of the problem?

Physical layer

In order to gather more information about traffic on your network, you have decided to copy all traffic going through a centralized switch to be forwarded to a computer using a packet sniffer. What configuration will need to be used on the switch in order for this to be accomplished?

Port mirroring

802.3af

Powered devices can draw up to about 13 W over the link. Power is supplied as 350mA@48V and limited to 15.4 W, but the voltage drop over the maximum 100 feet of cable results in usable power of around 13 W.

Character encoding, data compression and encryption/decryption take place at the

Presentation Layer

Which layers of the OSI model correspond to the TCP/IP model's Application layer?

Session, Presentation, Application

Which of the 2 protocols reside at the OSI transport layer?

TCP&UDP

Summarize the purpose of the Internet Engineering Task Force (IETF).

The Internet Engineering Task Force (IETF) focuses on solutions to Internet problems and the adoption of new standards. The IETF is governed by the Internet Architecture Board (IAB).

Summarize the functions of the Link layer in the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol stack.

The Link layer defines the host's connection to the network media and includes the hardware and software involved in the interchange of frames between hosts. The Link (or Network Interface) layer is the equivalent of the OSI Physical and Data Link layers. It defines the host's connection to the network media.

At which sublayer of the OSI model do network adapter cards operate?

The MAC sublayer of the Data Link layer

On a switched network, what configuration changes must be made to allow a host to sniff unicast traffic from all hosts connected to a switch?

The net adapter must be put in p-mode (promiscuous mode) and the switch must be configured to mirror traffic to the sniffer's port.

What is an I/G bit?

The part of a MAC address that determines whether a frame is addressed to an individual node (0) or group (1). If it is a 1, then this belongs to a multicast or broadcast transmission. MAC addresses that are made up of all 1s are broadcast addresses.

Deterministic media access can use a __________ to decide who's turn it is to transmit.

Token Ring

Summarize the role of Layer 6 in the Open System Interconnection (OSI) model.

Transforms data between the format required for the network and the format required for the application Layer 6 is known as the Presentation layer. This layer transforms data between the format required for the network and the format required for the application. The Application layer, Layer 7, provides an interface for software programs on network hosts that have established a communications channel to exchange data. The Session layer, Layer 5, represents the dialog control functions that administer the process of establishing the dialog, managing data transfer, and then ending the session. This can occur via simplex, half-duplex, or duplex. The Network layer, Layer 3, is responsible for moving data around a network of networks, known as an internetwork, using logical network and host IDs. The networks are often heterogeneous.

Frame

What is the name of the protocol data unit used at the OSI data link layer?

A switch could eliminate collisions by working in ____________.

tcpdump

What command is using tcpdump to capture traffic from the IP address 172.16.16.254 on the interface eth0 and output the results to the file router.pcap?

tcpdump -i eth0 -w 'router.pcap' src host 172.16.16.254