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
