Unit 1 Summary: Chapters 1,2,3,4
Chapter 1 – The TCP/IP and OSI Networking Models: * A network model sometimes also called either a networking architecture or networking blueprint refers to a comprehensive set of documents used to describe the functions of a network as a whole * The international organization for standardization (ISO) took on the task to create such a model, starting as early as the late 1970’s beginning work on what would become known as the open systems interconnection (OSI) networking model. * IP defines addresses for several important reasons. First each device that uses TCP/IP needs a unique address so that it can be identified on the network and IP also figures out how to group addresses together. * The term IP host refers to any device, regardless of size or power that has an IP address and connects to any TCP/IP network * The Current OSI Model: 1. Application 2. Presentation 3. Session 4. Transport 5. Network 6. Data Link 7. Physical
Chapter 2 – LAN Fundamentals: * File Sharing: Each computer can be configured to share all or parts of its file system so that the other computers can read, or possibly read and write, the files on another computer. * File Transfers: A computer could install a file transfer server, thereby allowing other computers to send and receive files to and from that computer. * The term collision domain defines the set of devices whose frames could collide * Broadcast Addresses: The most often used of the IEEE group MAC addresses, the broadcast address has a value of FFFF.FFFF.FFFF (hexadecimal notation) * Multicast Addresses: Multicast addresses are used to allow a subset of devices on a LAN to communicate.

Chapter 3 – WAN fundamentals: * The OSI physical layer, or Layer 1, defines the details of how to move data from one device to another. * Synchronization: The various devices need to synchronize their clocks so that they run at the exact same speed. * Service providers offer a class of WAN services, different leased lines that can be categorized as packet-switching services. * Point-to-point WANs can be used to connect a pair of routers at multiple remote sites
Chapter 4 – Class A, B, and C networks: * The main points needed to consider for sub netting: 1. Network Number 2. First Usable Address 3. Last Usable Address 4. Network Broadcast Address * Steps to sub netting: 1. Determine the class (A, B, or C)based on the first octet 2. Remember the number of network and host octets based on their class 3. To find the network number, change the IP address’s host octets to 0 4. To find the first address, add 1 to the fourth octet of the network ID 5. To find the broadcast address, change the network ID’s host octets to 255 6. To find the last address, subtract 1 from the fourth octet of the network broadcast address.