CCNA 01 Introduction to Internetworking Flashcards
<p>Describe name resolution and what device typically performs name resolution.</p>
<p>Name resolution is the matching up of the name of a computer or a website with its corresponding I P address. I P addresses are logical addresses, and name resolution is usually done by a Domain Name Server, or D N S for short.</p>
<p>How is communication accomplished over an L A N, or Local Area Network?</p>
<p>Communication over an L A N is done via hardware addresses known as MAC addresses. MAC addresses are Media Access Control addresses that are permanently burned into the Network Interface Card of hosts on a network. Communication over an L A N is NOT accomplished via I P addressing.</p>
<p>What is an Internetwork comprised of?</p>
<p>Two or more L A N's connected together using a Router.</p>
<p>What address is used by a sending host to communicate with a host on another network?</p>
<p>The hardware, or MAC address of the default gateway, which is usually the MAC address of the router of the network that the sending host is on. The sending host is not sending information to the receiving network, but rather to the default gateway. The router then sends the information to the receiving network.</p>
<p>Describe collision domains.</p>
<p>Collision domains are network segments with multiple hosts in which all hosts share the same bandwidth, typically created when using a hub. This creates collisions if more than one host tries to transmit at the same time. By plugging each host into a port on a Layer 2 switch, each host is effectively in its own collision domain, which eliminates network collisions.</p>
<p>A collision domain is broken up by \_\_\_\_\_\_\_\_\_\_\_\_\_\_, and a broadcast domain is broken up by \_\_\_\_\_\_\_\_\_\_\_\_\_\_.</p>
<p>Collision domains are broken up by switches, while broadcast domains are broken up by routers.</p>
<p>In which type of networks are broadcast domains broken up by routers?</p>
<p>Broadcast domains are only broken up by routers in Ethernet networks. When using serial or WAN links, routers do not break up broadcast domains.</p>
<p>How is communication between Virtual L A N'S (V LAN's) accomplished?</p>
<p>Communication between V LAN's can only be accomplished by using a router. Communicating between V LAN's is basically the same as communicating between two separate networks.</p>
<p>In essence, what is a Hub?</p>
<p>A multiport repeater that creates exactly one collision domain, and one broadcast domain.</p>
<p>What ports does a Hub amplify or send out signals on?</p>
<p>Every port on the hub except the port where the signal was originally received.</p>
<p>What does a Bridge do?</p>
<p>Bridges reduce collision domains within a broadcast domain by increasing the total number of collision domains. Bridging technology is accomplished in today's networks by using switches.</p>
<p>Switches are also referred to as what?</p>
<p>Multi-port bridges.</p>
<p>How does a switch segment a network?</p>
<p>By using MAC addresses.</p>
<p>Where are MAC addresses stored on a switch?</p>
<p>In the MAC address table, which is also known as a CAM table.</p>
<p>What is the command to view a MAC address table?</p>
<p>Show mac-address-table</p>
<p>What are the two types of layout in a network?</p>
<p>The physical layout and the logical layout.</p>
<p>In a network with no routers present, how many broadcast domains are there?</p>
<p>Routers break up broadcast domains, so if there are no routers in a network, that network is one large broadcast domain.</p>
<p>In a network with multiple switches, is the connection between two switches a separate collision domain?</p>
<p>Yes, each individual connection between switches is a separate collision domain.</p>
<p>Which layers of the O S I model do collision and broadcast domains operate at?</p>
<p>Collision domains operate at Layer 2 via switches, and broadcast domains operate at Layer 3 via routers.</p>
<p>True or false? Hardware addresses are passed through a router?</p>
<p>False. Hardware addresses are used to communicate on an L A N, but in order to communicate past a LAN's router, a.k.a. its default gateway, the logical I P address of the distant host is passed through the router.</p>
<p>What are the 7 layers of the O S I model?</p>
<p>Physical, Data Link, Network, Transport, Session, Presentation, and Application.</p>
<p>What are the upper layers of the O S I model?</p>
<p>Session, Presentation, and Application.</p>
<p>In the O S I model, from the Transport layer down to the Physical layer, what service is provided?</p>
<p>End to end, or host to host communication.</p>
<p>What 2 types of communication take place at the Transport layer?</p>
<p>Connectionless, unreliable communication, and connection-oriented reliable transportation.</p>
<p>Is connection-oriented data delivery guaranteed?</p>
<p>No, it is just more reliable than connectionless data delivery.</p>
<p>What type of addressing occurs at the Network layer?</p>
<p>Logical addressing, such as using an I P address.</p>
<p>When a packet is addressed at the network layer, which type of communication has a larger header?</p>
<p>Connection-oriented communication.</p>
<p>What is meant by M T U?</p>
<p>Maximum Transmission Unit is the most data that a sending host can send to the receiving host without overflowing the buffer of the receiving host. </p>
<p>What is managed at the Transport layer?</p>
<p>Segments.</p>
<p>What are the only two places where a packet can be sent?</p>
<p>Either broadcast over its local network, or sent to the MAC address of the default gateway for that network.</p>
<p>What is managed at the Network layer?</p>
<p>Packets.</p>
<p>What is managed at the Data Link layer?</p>
<p>Frames, which are packets with information attached to the front as well as the back.</p>
<p>Name 8 Application level examples.</p>
<p>Telnet, File Transfer Protocol (F T P), Simple Mail Transfer Protocol (S M T P), Trivial File Transfer Protocol (T F T P), H T T P, H T T P S, Simple Network Management Protocol (S N M P), and Domain Name Service (D N S).</p>
<p>Name 4 Presentation level examples.</p>
<p>Rich Text Format, Musical Instrument Digital Interface (MIDI), Quick Time Movies, and MPEG files.</p>
<p>What does the Session layer do?</p>
<p>It keeps application data separate.</p>
<p>What are the two protocols that operate at the Transport Layer?</p>
<p>Transmission Control Protocol (T C P) and User Datagram Protocol (U D P).</p>
<p>What 5 things happen during a T C P Reliable Connection?</p>
<p>1) A reliable, but not guaranteed session is established. 2) A virtual circuit is set up using port numbers. 3) Sequencing numbers each segment 4) Flow control stops the receiving host from overflowing its buffers. 5) Acknowledgements are used.</p>
<p>What are the 3 segments sent during a T C P 3-way Handshake?</p>
<p>Sync (SYN) segment is sent by Host A, Sync Acknowledgement (SYN ACK) is sent by Host B, and then Host A sends an Acknowledgement (ACK) segment.</p>
<p>What is Flow Control?</p>
<p>Flow control provides a mechanism for the receiver to control the transmission speed.</p>
<p>Where does Flow Control occur?</p>
<p>At the Transport layer.</p>
<p>What occurs during Windowing and Acknowledgements?</p>
<p>A receiving host receives data from the sending host, and acknowledges all received data. For any data that is not received, the receiving host alerts the sending host to resend whatever data was missed. This process is done dynamically with groups of data, not just one segment at a time. This allows for faster, more efficient transfer of data.</p>
<p>What 4 things do routers provide?</p>
<p>Internetworking, packet-switching, packet filtering, and path selection.</p>
<p>What does the Data Link layer receive from the Network layer?</p>
<p>Packets, which it then frames to send out on the physical network.</p>
<p>What 2 sublayers is the Data Link layer broken up into?</p>
<p>The MAC (Media Access Control) sublayer and the L L C (Logical Link Control) sublayer.</p>
<p>What IEEE standard governs Ethernet L A N's?</p>
<p>802.3 is the specification for Ethernet L A N's.</p>
<p>What IEEE standard governs Wireless?</p>
<p>802.11 is the specification for Wireless Ethernet L A N'S.</p>
<p>How many bytes make up a MAC address?</p>
<p>6 bytes, or 48-bits. The first 3 bytes (24 bits) are defined by the manufacturer.</p>
<p>What type of MAC address do serial and WAN connections use?</p>
<p>Serial and WAN connections do not use MAC addressing.</p>
<p>Wireless L A N's are an extension of what?</p>
<p>Ethernet networks.</p>
<p>What does the Physical layer define?</p>
<p>Electrical, mechanical, procedural, and funcational specifications for activating, maintaining, and deactivating the physical link between end systems.</p>
<p>In the O S I model, what is the order of getting data through the 7 layers?</p>
<p>Data (data stream from the top 3 layers), segments (transport layer), packets (network layer), frames (data link layer), and bits (physical layer).</p>
<p>Name 4 categories of L A N components.</p>
<p>Computers, Interconnections, Network Devices, and Protocols.</p>
<p>What type of topology is Ethernet?</p>
<p>Physical Star, Logical Bus.</p>
<p>A unicast is what type of communication?</p>
<p>One-to-one.</p>
<p>A broadcast is what type of communication?</p>
<p>One-to-many.</p>
<p>A multicast is what type of communication?</p>
<p>One-to-many when there are a specifically defined number of hosts.</p>
<p>A Cisco router interface is what type of interface?</p>
<p>A D T E, or data terminal equipment interface.</p>
<p>Describe a crossover cable.</p>
<p>Used to connect like devices, and the 1 to 3 and 2 to 6 pins are connected.</p>
<p>How do more advanced switches handle straight-thru or crossover cables?</p>
<p>They auto-detect the type of cable and make any necessary adjustments so the cable will work. Older switches do not do this.</p>
<p>Crossover cables connect what type of devices?</p>
<p>Like devices, such as switch-to-switch.</p>
<p>Straight-thru cables connect what type of devices?</p>
<p>Differing devices, such as a computer to a switch, or a switch to a router.</p>
<p>Describe a rolled (or rollover) cable?</p>
<p>The RJ 45 connections are exact opposites of each other, as if one end was flipped directly over to be the opposite of the other end. Pins 1 and 8 would match up, 2 and 7, 3 and 6, etc. Rolled cables are used to console into network devices.</p>
<p>Describe out of band management vs. in band management.</p>
<p>Out of band management is done from outside of the network via a console cable, while in-bound management is done from inside the network with utilities such as telnet, S S H, etc.</p>
<p>What does C S M A / C D stand for?</p>
<p>Carrier Sense Multiple Access/Collision Detection.</p>
<p>C S M A / C D is used for what devices?</p>
<p>Hubs or other devices that are only running half-duplex. It is not run in full-duplex networks.</p>
<p>What happens if a collision occurs on a C S M A / C D network?</p>
<p>All ports will run a Random Backoff Algorithm, and then each station will have an equal chance to resubmit data.</p>
<p>Define half-duplex vs. full-duplex.</p>
<p>Half-duplex can send and receive, but can only do one of them at a time, using one wire pair - one to transmit and one to receive. Full duplex can send and receive at the same time.</p>
<p>Write 4 things that happen when the number of devices increases on a half-duplex network.</p>
<p>Collisions increase, effective bandwidth - or throughput - decreases, there is increased delay, and increased congestion.</p>
<p>What is a "jam signal" when using C S M A / C D?</p>
<p>When the transmitting hosts jams other transmissions except for its own in order to avoid creating collisions.</p>
<p>Is C S M A / C D necessary in point-to-point connections?</p>
<p>No, because the direct point-to-point connections are full-duplex, and both points can send and receive at the same time.</p>
