Networking OSI and Protocols

Which of the following is considered a layer-3 address? (A) 192.168.2.200 (B) www.gleneclarke.com (C) COMPUTER1 (D) 00-AB-0F-2B-3C-4E

A. 192.168.2.200 A layer-3 address is a logical address that is assigned to the system. An example of a logical address is an IP address. A layer-2 address is the physical address, also known as the MAC address of the system 00-AB-0F-2B-3C-4E

Which protocol is responsible for converting the logical address to a physical address

ARP Address Resolution Protocol (ARP) is a network layer protocol that converts the IP address (logical address) to a MAC address (physical address).

Provides dynamic address mapping between an IP address and a hardware address

ARP Address Resolution Protocol

Which TCP/IP protocols are at the Network Access Layer of the TCP/IP model

ARP PPP Ethernet Interface Drivers

TCP/IP Layer represents data to the user, plus encoding and dialog control

Application

Enables a diskless workstation to discover its own IP address

BOOTP Bootstrap Protocol

Sue is having trouble understanding some network concepts and asks you to help identify address types. Which of the following is considered a layer-2 address? (A) 192.168.2.200 (B) www.gleneclarke.com (C) COMPUTER1 (D) 00-AB-0F-2B-3C-4E

D. 00-AB-0F-2B-3C-4E A layer-2 address is the physical address, also known as the MAC address of the system A layer-3 address is a logical address that is assigned to the system. An example of a logical address is an IP address. 192.168.2.200

Dynamically assigns IP addresses to client stations at startup and allows the addresses to be reused when no longer needed

DHCP Dynamic Host Configuration Protocol

Which TCP/IP protocols are at the Application Layer of TCP/IP model

DNS BOOTP DHCP SMTP POP IMAP FTP TFTP HTTP

Translates domain names, such as cisco.com into IP address

DNS Domain Name System

What is the automated service that matches resource names with the required IP addresses

DNS Domain Name System

Cisco-proprietary routing protocol

EIGRP Enhanced Interior Gateway Routing Protocol

Defines the rules for wiring and signaling standards of the network access layer

Ethernet

A reliable, connection-oriented, and acknowledged file-delivery protocol

FTP File Transfer Protocol

Sets rules that enable a user on one host to access and transfer files to and from another host over a network

FTP File Transfer Protocol

What application layer protocol is commonly used to support for file transfers between a client and a server

FTP File Transfer Protocol

What is the name given to the Ethernet MAC sublayer PDU

Frame physical addressing (MAC & LLC) occurs at Layer 2 (Data Link) of OSI PDU for Layer 2-Data Link are frames

Which two protocols are used to control the transfer of web resources from a web server to a client browser

HTTP HTTPS

A set of rules for exchanging text, graphic images, sound, video, and other multimedia files on the World Wide Web

HTTP Hypertext Transfer Protocol

A web client is sending a request for a webpage to a web server. From the perspective of the client, what is the correct order of the protocol stack that is used to prepare the request for transmission

HTTP>TCP>IP>Ethernet

The security administrator for your network has asked that you block ping messages from entering your network. What protocol would you block

ICMP ICMP is the protocol used by the ping command, so to block pings you need to block ICMP

Which TCP/IP protocol is responsible for error and status reporting

ICMP Internet Control Message Protocol (ICMP) is responsible for error and status reporting and runs at the network layer of the OSI model.

Provides feedback from a destination host to a source host about errors in packet delivery

ICMP Internet Control Message Protocol

Enables clients to access email stored on a mail server

IMAP Internet Message Access Protocol

Maintains email on the server

IMAP Internet Message Access Protocol

What TCP/IP protocol is responsible for logical addressing and routing functions

IP The Internet Protocol (IP) protocol is responsible for logical addressing and routing functions. The IP protocol runs at the network layer.

Addresses packets for end-to-end delivery over an internetwork

IP Internet Protocol

Packages messages into packets

IP Internet Protocol

Receives message segments from teh transport layer

IP Internet Protocol

Which TCP/IP protocols are at the Internet Layer of the TCP/IP model

IP NAT ICMP OSPF EIGRP

Provides instruction to a machine for the control of a specific interface on a network device

Interface driver

TCP/IP Layer determines the best path through the network

Internet

A hub operates at which layer of the OSI

Layer 1 Physical

OSI Layer involves the mechanical, electrical, functional, and procedural means to activate, maintain, and deactivate physical connections for bit transmissions to and from a network device

Layer 1 Physical

A bridge operates at which layer of the OSI

Layer 2 Data Link

A switch operates at which layer of the OSI

Layer 2 Data Link

OSI Layer involves exchanging data frames between devices over a common media

Layer 2 Data Link

Which layer of the OSI model works with frames

Layer 2 Data Link Layer 2 of the OSI model works with frames. This means that devices such as bridges and switches process frames because they are considered layer-2 devices. Note that at layer 3 the data being processed is called a packet because it has a layer-3 header, and at layer 4 the data is known as a segment.

What layer of the OSI model is responsible for routing and logical addressing

Layer 3 Network The network layer is responsible for logical addressing and routing path determination & logical addressing PDU-packets

At which layer of the OSI model would a logical address be encapsulated

Layer 3 Network

OSI Layer involves providing services to exchange the individual pieces of data over the network between identified end devices

Layer 3 Network

Which layer of the OSI model works with packets

Layer 3 Network PDU--packets When the layer-3 header has been added to the message, the message is known as a packet. Layer-3 devices such as routers process packets.

Which OSI Layer is concerned with end-to-end communication over the network

Layer 3 Network PDU-packets

A router operates at which layer of the OSI

Layer 3 Network - path determination & logical addressing PDU-packets

OSI Layer involves services to segment, transfer, and reassemble the data for individual communications between end devices

Layer 4 Transport

OSI Layer involves managing data exchange and interhost communication

Layer 5 Session

OSI Layer involves data representation and encryption

Layer 6 Presentation

Which layer of the OSI model supplies services that allow user to interface with the network

Layer 7 Application

OSI Layer involves providing the means for end-to-end connectivity between individuals in the human network using data networks

Layer 7 Application

At which layers of the OSI does Ethernet function

Layers 1 & 2 Physical Data Link

Translates IP addresses from a private network into a globally unique public IP address

NAT Network Address Translation

TCP/IP Layer controls the hardware devices and media that make up the network

Network Access

Name the TCP/IP Layers

Network Access Layer Internet Layer Transport Layer Application Layer

The TCP/IP Internet Layer is similar to which Layer of the OSI

Network--Layer 3

Hierarchial design based on areas

OSPF Open Shortest Path First

Link-state routing protocol

OSPF Open Shortest Path First

Open standard interior routing protocol

OSPF Open Shortest Path First

What is the general term that is used to describe a piece of data at any layer of a networking model

PDU protocol data unit

What is the application layer protocol for receiving e-mail over the Internet

POP3 POP3 is the Internet protocol for receiving e-mail, whereas SMTP is the Internet protocol for delivering e-mail.

Downloads email from the mail server to the desktop

POP3 Post Office Protocol version 3

Enables clients to retrieve email from a mail server

POP3 Post Office Protocol version 3

Provides a means of encapsulating packets for transmission over a serial link

PPP Point-to-Point Protocol

You are troubleshooting communication to a network by looking at the link light on the switch. What layer of the OSI model are you troubleshooting when looking at a link light?

Physical The physical layer of the OSI model deals with physical aspects of the network, such as the cables and connectors. A displayed link light simply means a connection exists.

Name the OSI Layers

Physical Data Link Network Transport Session Presentation Application

The TCP/IP Network Access Layer is similar to which Layers of the OSI

Physical --Layer 1 Data Link--Layer 2

What is the application layer protocol for delivering e-mail across the Internet

SMTP SMTP is the Internet protocol for delivering e-mail, whereas POP3 and IMAP are Internet protocols for receiving e-mail.

Enables clients to send email to a mail server

SMTP Simple Main Transfer Protocol

Enables mail servers to send email to other servers

SMTP Simple Main Transfer Protocol

The TCP/IP Application Layer is similar to which Layers of the OSI

Session Presentation Application

A user is viewing an HTML document located on a web server. What protocol segments the messages and manages the segments in the individual conversation between the web server and the web client

TCP

Which protocol is responsible for controlling the size and rate of the HTTP messages exchanged between server and client

TCP

Which transport layer protocol is responsible for reliable delivery

TCP TCP is responsible for reliable delivery. Note that UDP is a transport layer protocol but it is used for unreliable delivery

Enables reliable communication between processes running on separate hosts

TCP Transmission Control Protocol

Reliable, acknowledged transmissions that confirm successful delivery

TCP Transmission Control Protocol

Which TCP/IP protocols are at the Transport Layer of the TCP/IP model

TCP UDP

A best-effort, unacknowledged file delivery protocol

TFTP Trivial File Transfer Protocol

A simple, connectionless file transfer protocol

TFTP Trivial File Transfer Protocol

TCP/IP Layer supports communication between diverse devices across diverse networks

Transport

What layer of the OSI model is responsible for breaking the data into smaller segments?

Transport The transport layer is responsible for breaking the data into smaller chunks called segments The transport layer also provides end-to-end connections and reliability PDU--packet

The TCP/IP Transport Layer is similar to which Layer of the OSI

Transport--Layer 4

Which transport layer protocol is responsible for unreliable delivery

UDP User Datagram Protocol (UDP) is responsible for unreliable delivery, which means it does not track whether the data has been received at the destination.

Does not confirm successful datagram transmission

UDP User Datagram Protocol

Enables a process running on one host to send packets to a process running on another host

UDP User Datagram Protocol

PDU at Layer 1

bits

PDU at Layer 7

data

What is a benefit of using a layered model for network communications

fostering competition among device and software vendors by enforcing the compatibility of their products

Which PDU format is used when bits are received from the network medium by the NIC of a host

frame

PDU at Layer 2

frames

Which address provides a unique host address for data communications at the Internet Layer

logical address

PDU at Layer 3

packets

PDU at Layer 4

segments

What is a function of Layer 4 of the OSI model

to describe the ordered and reliable delivery of data between source and destination

How does the application layer on a server usually process multiple client request for services

uses support from lower layer functions to distinguish between connections to the service