Chapter 1 Network+
UDP datagram
- includes data from the application layer with added port and length numbers plus a check sum - lacks most extra fields in TCP segments - doesn't care if receiving computer gets data
WHAT ARE THE TWO PRIMARY PARTS OF A MAC ADDRESS?
First 6 digits represent the number of the NIC manufacturer (organizationally unique identifier) Last 6 digits represent manufacturers unique serial number for that NIC (device ID)
PRIMARY FUNCTIONS OF LAYER ONE
Layer 1 - Physical - Method of moving data between computers. In this layer we look at control boxes & cabling. Physical Layer doesn't care what data goes through, as long as it goes.
Campus/core backbone
connection several different buildings
Backbone Distribution
connection within a building
NICs encapsulate data into a ______________ for sending that data over a network
frame
Which TCP/IP layer includes Layers 5-7 from the OSI seven layer model? A. Application layer B. Transport layer C. Internet layer D. Link layer
A. Application layer
The term "unshielded twisted pair" describes which of the following network components? A)cable B)hub C)router D)NIC
A. Cable
Which components work at Layer 1 of the OSI seven layer model? A. Cables B. Hub C. Network Protocol D. Session software
A. Cables & B. Hub
What component of Layer 2 of the OSI seven layer model creates and addresses the frame? A. MAC sublayer B. LLC sublayer C. CRC sublayer D. Data link sublayer
A. MAC sublayer
Which of the following OSI layers converts the ones and zeroes to electrical signals and places these signals on the cable? A)physical layer B)transport layer C)network layer D)data link layer
A. Physical layer
Packets Segments Datagrams
Application Layer: create the data Transport Layer: breaks the data into chunks Internet Layer: adds the IP addressing and creates the IP packets Link Layer: wraps the IP packet into a frame with MAC address information and a frame check sequence
Addressing 3
Application layer www.mtsu.edu Network Layer -Software (IPv4 example) 144.167.10.3 Data Link Layer -Hardware (MAC address) AF:00:8A:2C:3F:7C
How much data can a typical frame contain? A) 500 bytes B) 1500 bytes C) 1500 kilobytes D) 1 megabyte
B. 1500 bytes
A says complete 48-bit MAC addresses are allocated to NIC manufactures from the IEEE. Buster says IEEE only assigns the first 24 bits to manufactures Carlos says the IEEE assigns only the last 2 bits to manufactures. Who is correct? A. Only A is correct B. Only Buster is correct C. Only Carlos is correct D. No one is correct
B. Buster is correct. The IEEE assigns the organizationally unique identifier (OUI) portion of a block of MAC addresses, which is the first six digits (or 24 bits). The manufacturer is responsible for the last 24 bits, the unique device ID.
If a sending system does not know the MAC address of the intended recipient system, it sends a broadcast frame with what MAC address? A. 192.168.0.0 B. FF-FF-FF-FF-FF-FF C. 11-11-11-11-11-11 D. 00-00-00-00-00-00
B. FF-FF-FF-FF-FF-FF
Which protocol creates the final IP packet? A. NIC B. IP C. TCP D. UDP
B. IP The internet protocol takes the UDP datagram or TCP segment, adds IP addressing information, and wraps it up into an IP packet, bound for the frame
Which layer of the OSI model makes sure the data is in readable format for the Application layer? A. Application layer B. Presentation layer C. Session layer D. Transport layer
B. Presentation layer
From the options that follow, select the one that best describes the contents of a typical (simplified) network frame. A) Sender's MAC address, recipient's MAC address, data, FCS B) Recipient's MAC address, sender's MAC address, data, FCS C)Recipient's IP address, sender's IP address, data, FCS D) Recipient's email address, sender's email address, data, FCS
B. Recipient's MAC address, sender's MAC address, data, FCS The contents of a simplified network frame are Recipient's MAC address, sender's MAC address, data, FCS in that order.
Which of the following is most lieklyto be a MAC address assigned to a NIC? A) 192.166.1.121 B) 24.17.232.7B C) 23.4F.17.8A.4C.10 D) 713.555.1212
C. 23.4F.17.8A.4C.10
Which of the following best describes an IP address? A) A unique dotted decimal notation burned into every NIC B) A unique 48- bit identifying nuber burned into every NIC C) A dotted decimal notation assigned to a NIC by software D) A 48- bit identifying number assigned to a NIC by software
C. A dotted decimal notation assigned to a NIC by software
Which layer of the TCP/IP model involves routing? A) Link layer B) Transport layer C) Internet layer D) Application layer
C. Internet layer
At which layer of the TCP/IP model are UDP datagrams created? A. Link/network interface B. Internet C. Transport D. Application
C. Transport Data is divided into chunks at the Transport layer and then bundled into UDP datagrams or TCP segments, depending on which protocol is used
connection oriented protocol vs connectionless communications
Connection oriented protocol - TCP transmission control protocol Connectionless protocol - UDP User datagram protocol
numbering systems (3)
Decimal (0-9) Binary (0&1) Hexidecimal (0-9 & A-F)
Who created the OSI Seven Layer Model?
Developed by ISO, International Organization for Standardization
HOW LONG IS A MAC ADDRESS (HEX, BITS, & BYTES)?
Each MAC address is 12 hex characters, 48 bits in length, 6 bytes, 1500 max
WHAT IS THE UNIVERSAL MAC ADDRESS FOR A BROADCAST?
FF-FF-FF-FF-FF-FF used if MAC address is not known so destination device can send its MAC address
The ______ is an example of software that creates packages for moving data across networks.
Internet Protocol (IP)
PRIMARY FUNCTIONS OF LAYER THREE
Layer 3 - Network - where packets are created & addressed to go to another network. IP & ROUTING! -large networks need logical addressing method (creates subnets) -network protocol - creates unique identifiers as well as rules how to handle data in TCP/IP protocol suite - addresses: physical- MAC address, burned into chips Logical- IP address - dotted decimal numbers four 8-bit numbers (0-255) configured by network admin or end user - router - connects subnets using IP address. strips off incoming frame, decides where to send data, creates new frame, sends packet along - layer 3 LAST LAYER to deal with hardware
The __________ provides the key interface between the Physical (layer 1) and Network (layer 3) layers
Layer 3 Data Link Layer
PRIMARY FUNCTIONS OF LAYER FOUR
Layer 4- Transport layer - assembles & disassembles software, packetizing-End to end management - initiates requests for packets not received in good order -segments into segments & datagrams (chunks) -TCP - Transmission Control Protocol - connection oriented -UDP- Datagram Protocol - connectionless - Links to the App Layer
PRIMARY FUNCTIONS OF LAYER FIVE
Layer 5 - Session - Opens, manages, closes sessions Connects Apps to apps (printer to PC)
PRIMARY FUNCTIONS OF LAYER SIX
Layer 6 - Presentation - puts data in readable format from lower layers to application layer, some encryption
WHAT ARE THE LAYERS OF THE OSI (OPEN SYSTEM CONNECTION) MODEL? All People Should Take New Directions Living More Purposefully!
Layer 7 - Application Layer 6 - Presentation Layer 5 - Session Layer 4 - Transport Layer 3 - Network Layer 2 - Datalink Sublayers: Logical Control Link & Media Access Control Layer 1 - Physical All People Should Take New Directions Living More Purposefully!
PRIMARY FUNCTIONS OF LAYER SEVEN
Layer 7 - Application - allows users to exchange data on a network -code -API - Application Programming Interfaces - used by programmers to make their programs "network aware". Allows programmers to enhance or extend app capabilties - HTTPS, DNS, FTP, SSH Telnet SMTP, POP
PRIMARY FUNCTIONS OF LAYER TWO
Layer Two - Data Link Layer - message delineation Any device that deals with a MAC address -NIC - network interface card - interface b/t PC & network -ETHERNET 2 Sublayers: 1. Logical Link Control- the aspect of the NIC that talks to the system's operating system (usually via device drivers) 2. Media Access Control- creates& addresses the frame,checks FCS, completes frames sent along network cabling
LAN
Local Area Network - network within a local area
Every NIC has a hard coded identifier called a __________
MAC address
WHAT IS A MAC ADDRESS?
Media Access Control - a unique address burned into a ROM chip on the NIC
What are the parts in a generic frame?
Reciepent's MAC address Senders MAC address type- indicates specific network technology of frame data FCS- Frame check sequence (error checking) Most frames hold 1500 bytes of data enclosed within a packet at layer 3
HOW DOES THE TCP/IP MODEL COMPARE TO OSI?
TCP/IP Model - descriptive model Application - combines layers 5,6,&7 of OSI, uses unique port numbering system to give app number between 1 &65,535 Transport - combines layers 4,5,&7 of OSI, assembly & disassembly of data, connection oriented & connectionless communications Internet - IP packet layer, describes layer 3 of OSI, routers at this layer Link/ Network Interface - describes layers 1 & 2 of OSI, complete frames *no standards body - many variations, version 1 (four layers) most common OSI - perscriptive model - couldn't describe IPX/SPX & NetBIOS/NetBEUI
The ________ provides an excellent tool for conceptualizing how a TCP/IP network works. (select the best answer)
Transmission Control Protocol / Internet Protocol (TCP/IP) model. OSI seven layer model does a good job as well but not perfectly matched to TCP/IP networks like the TCP/IP model)
On a sending machine, data gets broken up at the ______________ of the OSI seven layer model
Transport Layer - Layer 4
most commonly used cabling
Unshielded Twisted Pair
WAN
Wide Area Network- network extends over long distance
Using the ________ enables a computer to send a packet that every other PC on the network will process
broadcast address
Types of control boxes
hubs- "dumb boxes" directly copy frames to all systems, exact copy of NIC would then process the frame switches- replaced hub. filter traffic by MAC address to send to exact MAC address
oscilloscope
measures voltage on wire to see electrical pulses
Most often, the __________ provides the physical connection between the PC and the network.
network interface card NIC
A __________ enables multiple machines to connect over a network
switch
