WGU C172 Introduction to Networking Concepts (latest update 2023)

TCP/IP - Answer stands for transmission control protocol/internet protocol and is a set of protocols used to connect network devices to each other. Application Layer - Answer This layer is responsible for the communication protocols between nodes. The protocols in this layer include hypertext transfer protocol (HTTP and HTTPS), Secure Shell (SSH), and network time protocol (NTP), among many others. Transport Layer - Answer This layer is responsible for the end-to-end transport of data. The protocols that live in this layer are transmission control protocol (TCP) and user datagram protocol (UDP). Network Layer - Answer This layer defines the logical transmission protocols for the whole network. The main protocols that live in this layer are internet protocol (IP), internet control message protocol (ICMP), and address resolution protocol (ARP). Network Interface Layer - Answer This TCP/IP model layer establishes how data should be physically sent through the network. OSI (Open System Interconnection) model - Answer model consists of a seven-layer architecture that organizes the sending of data from hosts across a network OSI (Open System Interconnection) model - Answer was developed by the International Standards Organization (ISO) after the TCP/IP model to provide greater granularity of networking assignments within the model. Physical Layer - Answer This layer is responsible for the physical connections of the devices in the network. This layer is implemented through the use of devices such as hubs, repeaters, modem devices, and physical cabling. Data Link Layer - Answer This layer is responsible for the error-free delivery of data to the receiving device or node. This layer is implemented through the use of devices such as switches and bridge devices, as well as anything with a network interface, like wireless or wired network cards. Network Layer - Answer This layer is responsible for the transmission of data between hosts in different networks as well as routing of data packets. This layer is implemented through the use of devices such as routers and some switches. Transport Layer - Answer This layer provides services to the application layer and receives services from the network layer. It is responsible for the reliable delivery of data. It segments and reassembles data in the correct order for it to be sent to the receiving device. It may also handle the reliable delivery of data and any retries of data that are lost or corrupted (for example, TCP does this). This layer is often called the heart of OSI. Session Layer - Answer This layer is responsible for connection establishment, session maintenance, and authentication. Presentation Layer - Answer This layer is responsible for translating data from the application layer into the format required to transmit the data over the network as well as encrypting the data for security if encryption is used. Application Layer - Answer This layer is responsible for network applications (like HTTP or FTP) and their production of data to be transferred over the network. Layer 1 Physical - Answer Receives the frames and data and sends them via the local media (copper wires, fiber-optic cables, etc.) to the switches, routers, etc., along the network path. All of this takes a matter of microseconds to achieve. Layer 2 Data Link - Answer Receives the packets and adds physical addressing by adding sender and receiver MAC addresses to each data packet. This information forms a unit called a frame. Layer 3 Network Layer - Answer Receives the segments and transmits them across the network as packets. As you are accessing the website, this Layer adds the source and destination IP addresses to each individual data packet. The destination IP address will be the router on the network that will move data off the local network. The series of routers between that router and the destination server will determine how the packet is moved across various networks between them. Layer 4 Transport - Answer Data is transferred and is then segmented and numbered to send the data across the network in sizes the network can handle (typically around 1,500 bytes maximum) and to reassemble it in the correct order by the webserver. Layer 5 Session - Answer Establishes the connection between your laptop and WGU's server and maintains it while you accomplish your tasks on the website. Layer 6 Presentation - Answer The command is then sent to this Layer to be encrypted as it is sent (and decrypted when received by the webserver). Layer 7 Application - Answer You open a web browser on your laptop and type into the search bar. Modem - Answer A device necessary for sending and receiving data. Allows computers to transport digital information over analog lines, such as phone or cable lines. Router - Answer a point of connection between two or more networks that forwards dat packets between the networks. Router - Answer Layer 3 device, makes it's forwarding decisions based on logical network addresses. Switch - Answer Layer 2 device used to connect devices in a specific network and allows them to communicate efficiently within the network. Bridge - Answer Layer 2 device similar to a router in that it connects two or more networks, but it simply forwards the data to the next network without analysis. Repeater - Answer a layer 1 device that strengthens, replicates, or regenerates signals that are weakened during transmission. Hub - Answer Layer 1 device takes the data packets from the router, and sends them to all the devices connected on the network. UTP Cables - Answer These cables are created when pairs of wires are twisted around each other to protect and cancel out interference from each other and outside sources Cat3 - Answer supports up to 10 Mbps (Megabits per second) for up to 100 meters and is commonly used for phone lines today. Cat4 - Answer supports 16 Mbps for up to 100 meters and is not commonly used today. Cat5 - Answer is used in Ethernet LANs containing two twisted pairs allowing for up to 100 Mbps up to 100 meters between the device and the switch, hub, or router. This has been practically replaced by the Cat5e specification. Cat5e - Answer doubles the number of twisted pairs to four for up to 1 Gbps (Gigabits per second) over up to 100 meters. Cat6 - Answer is also used in Ethernet LANs and data centers. is made up of four tightly woven twisted pairs (more twists per linear foot) and supports 1 Gbps for up to 100 meters or 10 Gbps for up to 55 meters. Cat6a - Answer is an improvement of the Cat6 standard, supporting the same standards and lengths (with the ability to run 10 Gbps over 100 meters maximum), but using a higher quality cable that is more resistant to interference. This is most commonly used in wired networks today. RJ11 - Answer A connector that supports two pairs of wires (four total); typically used in telephones. RJ45 - Answer This is an end connector typically used with Ethernet cables and supports four pairs (eight wires). Coaxial cables - Answer analog cables made of copper but specifically engineered with a metal shield intended to block signal interference. coaxial cables - Answer are mostly used by cable TV companies to connect their customers to the company's facilities. Fiber cables, or fiber-optic cables - Answer use glass or plastic threads within cables to transfer the data using light (lasers or LEDs) as opposed to traditional metal cables using electricity. Single-mode cables - Answer made up of one single glass or plastic fiber. The benefit of a single fiber cable is the ability to carry higher bandwidth for 50 times the distance of a multimode cable. This requires higher cost electronics to create the light and thus is typically used for longer distances (hundreds or thousands of kilometers) and higher bandwidth applications. Multimode cables - Answer wider in diameter due to light modes being sent across the cable. Multimode fibers are highly effective over medium distances (500 meters or less at higher speeds) and are generally used within a LAN. They are also less expensive than single-mode fiber due to the potential for use with LEDs and other lower-cost options for creating the light. ping - Answer one of the most basic tools for testing connectivity to other hosts useful in troubleshooting connectivity with other devices traceroute/tracert - Answer used to trace the route an IP packet takes to a destination isplays each hop (next router) in a numerical list with the hop's IP address and the time it takes to receive the packet traceroute - Answer used for Linux systems tracert - Answer used for Windows systems traceroute/tracert - Answer can be useful in determining where a ping fails, troubleshooting performance issues, and other aspects regarding connectivity. tracepath - Answer is similar to traceroute or tracert in that it displays the path taken by a packet from its source to its destination. This command is useful because it can be used by any user instead of needing superuser privileges. It is primarily used in Linux. ipconfig - Answer provides the user with the IP, subnet mask, and default gateway for each network adapter by default with the /all option information, such as MAC address, DHCP status, and lease information. ifconfig - Answer used to configure the kernel network interfaces. It is implemented at the time of booting to configure the necessary interfaces. Once the interfaces are configured, it is used for debugging or tuning the system. It is primarily used in Linux. ARP - Answer displays the IP to physical (MAC) address mappings for hosts that have been discovered in the ARP cache. ARP can be used to add, remove, or modify entries in the ARP cache. netstat - Answer displays information about active ports and their state and can be useful in troubleshooting and capacity management. It is available in Windows, MacOS, and Linux.