OSI Model Exam Review (2022/2023) Already Passed

OSI Model Exam Review (2022/2023) Already Passed Domain Name System (DNS) ✔✔The primary name resolution service used on the Internet and in Microsoft networks. Resolves host names to IP addresses. Also used to locate ...

OSI Model Exam Review (2022/2023) Already Passed Domain Name System (DNS) ✔✔The primary name resolution service used on the Internet and in Microsoft networks. Resolves host names to IP addresses. Also used to locate servers running specific services with a Microsoft network. Hypertext Transfer Protocol (HTTP) ✔✔Primary protocol used to transmit data across the Internet for web pages. HTTPS is a secure version used to transmit data in an encrypted format. File Transfer Protocol (FTP) ✔✔Protocol used to transfer files to and from this server. Servers are commonly hosted on the Internet. File servers are used on internal networks to host files needed by users. The original commercial version of Ethernet supported 10 Mbps bandwidth, the version introduced in the early 1990s supports 100 Mbps; and in 1998, Gigabit Ethernet was introduced. All versions use the same data frame formats, with the same maximum PDU sizes, so they can interoperate freely. Given this information and what you know of layered technologies, which of the following statements is true? ✔✔Ethernet works at the Data Link and Physical layers of the OSI model, and upgrades to newer, faster versions of Ethernet can be made by changing only the components that work at these layers. Changes in technology at one layer of the OSI model don't usually affect the operation of other layers. The addition of information to a PDU as it's passed from one layer to the next is called? ✔✔PDI transforming Layers acting as though they communicate directly with each other across the network are called? ✔✔Peers Place the following letters in the correct order to represent the OSI model from Layer 7. ✔✔Application -7 Presentation -6 Session -5 Transport-4 Network -3 Data Link -2 Physical -1 Which OSI layer creates and processes frames? ✔✔2- Data Link Which OSI layer handles flow control, data segmentation, and reliability? ✔✔4- Transport Which OSI layer governs how a NIC is attached to the network medium? ✔✔1- Physical Which OSI layer determines the route packet takes from sender to receiver? ✔✔3- Network Which OSI layer is responsible for setting up, maintaining, and ending ongoing information exchanges across a network? ✔✔5- Session Which of the elements might the Data Link layer add to its PDU? ✔✔Physical addresses CRC When and how many times is a CRC calculated? ✔✔At the source and destination and at each intermediary device Which OSI layer does Project divide into two sublayers? ✔✔2- Data Link What are the names of the sublayers specified as a part of Project 802? ✔✔Logical Link Control (LLC) Media Access Control (MAC) Which terms refers to stripping header information as a PDU is passed from one layer to a higher layer? ✔✔Deencapsulation Which IEEE 802 standard applies to Ethernet? ✔✔802.3 Which IEEE 802 standard applies to wireless LANs? ✔✔802.11 What is the name of the PDU at the Transport Layer? ✔✔Segment At which OSI layer does the PDU contain sequence and acknowledgement numbers? ✔✔4- Transport Which of the following is an example of software found at the Application layer? ✔✔FTP HTTP At which Data Link sublayer does the physical address reside? ✔✔Media Access Control (MAC) Which of the following problems can occur at the Physical Layer? ✔✔Signal errors caused by noise A computer can access resources on the local LAN but not on a different subnet. You find that the computer's default gateway isn't configured correctly. Which OSI layer is this? ✔✔3- Network Layer You can ping a computer you're trying to transfer files to via FTP, but you can't communicate by using FTP. Which OSI layer is this? ✔✔7- Application Layer You check some statistics generated by a network-monitoring program and discover that an abnormally high number of CRC errors were detected. Which OSI layer is this? ✔✔2- Data Link Layer A computer won't connect to the network. After some investigation, you find that the patch cable isn't terminated correctly. Which OSI layer is that? ✔✔1- Physical Layer You receive an encrypted text file, but when you open it, the text is unreadable. You determine that decryption didn't take place as it should have. Which OSI layer is this? ✔✔6- Presentation Layer All computers connected to a particular hub have lost network connectivity. You determine that the hub is the problem. Which OSI layer is this? ✔✔1- Physical Layer One of your servers has been exhibiting sluggish network performance. You use a networkmonitoring program to try to evaluate the problem. You find considerable TCP retries occurring because the server is being overwhelmed by data, and packets are being discarded. Which OSI layer is this? ✔✔4- Transport Layer A user is trying to connect to another computer, but the logon attempt is continually rejected. Which OSI layer is this? ✔✔5- Session Layer You try to access a Linux server to share files by using NFS. You can communicate with the server, but the shared files don't appear to be available. Which OSI layer is this? ✔✔7- Application Layer You inspect a computer that isn't able to communicate with other computers. You find that IPv6 instead of IPv4 is installed on that computer. Which OSI layer is this? ✔✔3- Network Layer Application Layer ✔✔interfaces to access the network (DHCP, HTTP, FTP, etc) PDU = Data attach/interact network services (HTTP) Presentation Layer ✔✔presents the data (either generic in format/reassembles for delivery to App Layer) PDU = Data Streamline/generalization Data (common) compression/decompression encryption/de-encryption Session Layer ✔✔Establishes session before data sent does checkpoints and synchronization authentication protocols PDU = Data establish connect (x <-> y) 3 way handshake: 1. syn 2. syn/ack 3. ack Transport Layer ✔✔PDU = Segment MTU (maximum transmission unit) = 1518 bytes for Ethernet Flow Control and Sequence Source and Destination Port #'s TCP ensures reliable delivery - connection oriented Network Layer ✔✔PDU = Packet IP address - connectionless Access control - routing process routers/ layer 3 switch IPv4 IPv6 Data Link Layer ✔✔PDU = Frames MAC address Source and Destination Media Access Control FCS frame check sequence (form of CRC error handling) - recalculated between routers NIC driver - software aspect Switches Physical Layer ✔✔PDU= Bits and Bytes encoding/de-encoding MTU (Media Transmission Unit) 1518 bytes for Ethernet Flow and Control Sequencing Source and destination port numbers Port 80 ✔✔HTTP Network Layer Examples ✔✔Firewalls