Network and Security Foundations - D315 Test Questions with Complete Solutions, RATED A+

TCP/IP - model that is a common set of protocol standards that permits the appropriate transmission of data; used for practical application when locating specific protocol TCP/IP layers - application, transport, network, network interface OSI - model that enables transmission of data among hosts on a network; widely used in network documentation and discussions OSI layers - Application, Presentation, Session, Transport, Network, Data Link, Physical Open Systems Interconnection (OSI) - OSI acronym TCP and OSI - set of procedures that sends data from one host to another. Can be done over the internet, network, or any form of communication TCP Network Interface Layer - Physical cabling and wireless spectrum OSI - Physical Layer - cables and connectors; establishes how a signal is transmitted via wires or airwaves; responsible for the physical connections of the devices in a network; use hubs, repeaters, modem devices and cabling OSI - Data link layer - contains network card and Media Access Control (MAC) address; responsible for error-free delivery of data to the receiving device or node; switches, bridges, or wireless/wired network cards Network Layer (TCP and OSI) - Internet Protocol and Internet Control Message Protocol (ICMP); define one protocol versus another for connecting networks Transport Layer (TCP and OSI) - ensures data is transferred to the correct application; Transmission Control Protocol (TCP) or User Diagram Protocol (UDP) Transmission Control Protocol (TCP) - type of transport layer; verifies data and resends if not delivered User Diagram Protocol (UDP) - type of transport layer; unreliable to the extent that it does not guarantee redelivery of the data; preferred in audio streaming TCP - Application Layer - HTTP for a web broswer; SMTP for email; DNS; Secure Shell (SSH); network time protocol (NTP); communication protocol between nodes OSI - Session Layer - establishes the session and ensures things are working correctly end-to-end OSI - Presentation Layer - takes care of data encryption; translating data from the application layer into format required to transmit data; OSI - Application Layer - HTTP; DNS; File transfer protocol (FTP); responsible for network application; production of data to be transferred over the network OSI layers by number - Physical 1; Data Link 2; Network 3; Transport 4; Session 5; Presentation 6; Application 7 TCP Transport Layer - responsible for end-to-end transport data; TCP and UDP TCP Network Layer - logical transmission protocols for the whole network; IP, Internet Control Message Protocol (ICMP), address resolution protocol (ARP) TCP Network Interface Layer - establishes how the data should be physically sent through the network OSI - Network Layer - responsible for the transmission of data between hosts in different networks as well as routing data packets; use routers and some switches OSI - Transport Layer - receives services from network layer and provides services to the application layer; responsible for reliable delivery of data; segments and reassembles data in the correct order for it to be sent to the receiving device; handle reliable delivery of data that are lost or corrupted (TCP does this); heart of OSI Switch - found with OSI data link; standalone or integrated with other devices; keeps traffic between the source and destination ports from interfering with other devices on the network; Router - found with OSI network layer; connect home network to the internet; connect web server to database server; Firewalls - found in OSI layers data link, network, transport, session, and application; defines what traffic should go between two networks; can be software that runs in virtual machine or physical server like hardware Firewall Layer 4 - operates the network and transport layers; Firewall Layer 7 - operates at session, presentation, and application layers; decrypt and analyze the content flowing through Modem - A device necessary for sending and receiving data. Allows computers to transport digital information over analog lines, such as phone or cable lines; DSL or satelite; found in data link and physical Repeater - A device used to strengthen, replicate, and regenerate signals that are weakened during transmission; range extender is a form that takes distored Wi-Fi signal and transmits it to the formerly dead zone in large homes Hub - device that connects the router to the network; takes the data packets from the router and sends them to all devices connected on the network (e.g. USB hub) Unshielded Twisted Pair (UTP) - the tighter the twists of cables, the lesser electrical interference that occurs and higher the category of the cable