SYS 140 Week 9 Journal - ryanm292002/Ryans-Repository GitHub Wiki

WEEK 9 Reading

Networking Overview

A computer-related network can be described as two or more devices that have the ability to communicate and send resources between the devices. These resources can be anything from various types of files to emails to sharing a physical device like a printer. PAN networks are very close proximity communications among devices that are connected through wires but also wireless connections, keyboards, desktops, mobile devices are examples of Personal Area networks. Local Area networks are groups of devices that share resources in a set local area, which could be maybe one room or one home or one building, these are all local area networks. MAN is basically the connections between two or more different LANS set in the same city. A college with spread-out campuses among a city would be a MAN. WAN connects two or more LANs across a larger geographical scale, so a Verizon building in Boston's connection with a Verizon building says in New York would be a WAN. WLAN is basically any wireless network, it consists of a wireless device and an access point for the device to connect to. WWAN is a wireless WAN, it uses multiple different types of technologies. WMN is a type of network that doesn't need an access point, instead, it passes data among radio devices.

Network Topologies

The topology of a network is basically the description of how a network is wired/ what devices it uses to function. Ethernet is the most popular type of LAN where network devices connect to a central device, they are usually connected with RJ-45 wires. Switches are more reliable than hubs to use as a central device because when hubs are used then every time data is sent then a delay occurs.

OSI Model

The OSI model can be described as a summarization of the whole process of sending and receiving data when devices are networking, the model separates each part of the process into different layers making it easier to read. Each layer does its part and results in a function that will help the next layer above it to start working. From top to bottom the layers go: application, presentation, session, transport, network, data link, physical.

TCP/IP Model

TCP/IP is the most commonly used network protocol today. When comparing to the OSI model, instead of 7 layers this model only has 4 layers, there are fewer layers because there are more protocols in each layer that are producing the sharing of data. From top to bottom the TCP/IP model goes from the application layer, transport, internet, and then network access.

Network Addressing

When studying different network adapters, there'll usually be two different kinds of addresses that are assigned to the adapters, usually, a MAC address which I relate to more the address that makes a piece of hardware unique, its the address for the actual hardware, while IP addresses are for identifying the device when it's on a network, IP addresses can either be IPv4 or IPv6, devices today have a little bit of both types of addresses. Class A: 10.0.0.0, Class B: 172.0.0.0, Class C 192.0.0.0.

More IPv4 addressing

When looking at an IP address you can break it into separate parts to make it more identifiable. The network number is the part that tells you which network the computer is on, if you have two computers in the same network they will have the same network number. The host address is basically the part that identifies a specific computer, no two devices in the same network will have the same host address. In Class A, the first part is a network, the last 3 parts are all represented by a host portion. In class B the first two portions represent the networking numbers while the second two represent the host numbers. In class C the first 3 represents network numbers while the last section is reserved for host numbers. Besides giving a device a unique IP address, there'll also be a subnet mask that is assigned which helps the computer determine which parts of the IP address are dedicated to the network and which sections are dedicated to the host.

Network Troubleshooting

When something doesn't work in a network there are many steps in order to fix the problem the right way. The biggest step is to take count of all the devices connected in a network, anyone of them could be causing the problem. The ping command is very useful cause it can be used to check if there is or isn't connectivity between two IP addresses that are assigned to devices in the network. If a ping is unsuccessful it's easy to pinpoint that's where the problem needs fixing.

GUIDING QUESTIONS

How would you classify Champlain's network (for example, is it a PAN, LAN, or WAN)? Justify your answer.

I would classify chaplains network as WAN because there are multiple buildings on campus where devices connect amongst each other, PAN is more for connections among personal devices, and when I think LAN I think one singular building at most.

Between the OSI and TCP/IP Model, which one seems more useful for describing networks? Justify your answer.

I think as a general description that OSI would be actually better because it's more basic than the TCP/IP model. The TCP/IP model with its protocols is for troubleshooting network connections not describing them, with the OSI it's much more simple to pick out a general layer that describes a lot of parts of a network in one layer.

Suppose Champlain College has given a Class A network ID for its network (i.e., it had 224 addresses to assign to computers). Give one reason why this would be a good thing and one reason why this might be a bad thing.

Well first off class A networks are good for very large networks, they'll be a large IP pool that will last well into the future, the cons would be that you're security would be weak if all departments of Champlain was all tied into the Class A network pool, it would also just be in general harder to maintain and analyze all the data and connections that are taking place in one big pool of IP addresses.

Suppose a colleague came to you and said that they could not connect to a website. How might you use some or all of the network tools from this chapter to diagnose the problem?

You could use the protocols and the troubleshooting we learned to diagnose the problem. I would first figure out what device the device that's not connecting is supposed to be connected to, I would run ping commands between the non-working device and the network device to figure out if they're even connected in the first place.