ITC330 Midterm Exam Topics (Finished - Long Version).docx

**Network Models (Module 1):** - **Peer to Peer Model:** Understand how each computer manages its own resources. - The Operating System (OS) of each computer on the network is responsible for controlling access to its resources - No centralized control - C...

**Network Models (Module 1):** - **Peer to Peer Model:** Understand how each computer manages its own resources. - The Operating System (OS) of each computer on the network is responsible for controlling access to its resources - No centralized control - Computers, called nodes or hosts, form a logical group of computer and users - each computer controls its own administration, resources, and security - Advantages - Simple configuration - Less expensive compared to other network models - Disadvantages - Not scalable - Not necessarily secure - Not practical for large network environments - Rule of thumb: - If the network supports fewer than 15 computers, a peer-to-peer network is the way to go - **Client-Server Model:** Know how resources are managed by the Network Operating System (NOS), including Domain/Active Directory, Exchange server, NAS. - NOS manages resources by acting as a central hub, where clients request access to data or services hosted on the server, which then process the requests and delivers the desired information back to the client - Active Directory: - Centralized management: AD manages user accounts, security policies, and network resources - Domain services: AD Domain Services handles authentication and access control - Clients access networked devices and resources based on AD permissions - Exchange Server - Provides a centralized platform for storing, sending, and receiving emails, allowing users to access their mailboxes through email clients - Facilitates sharing and management of calendars and contact information across the network - Enables features like shared mailboxes and public folders for team collaboration - Network Attached Storage(NAS) - Dedicated device for storing and managing files accessible by multiple users across the network, offering easy file sharing and backup capabilities - Can implement data redundancy features to ensure data availability in case of hardware failure - Users access NAS storage via standard network protocols like SMB, making it easy to manage files from different devices **Network Types and Topologies:** - Understand the characteristics of LAN, CAN, WAN (pg.16). - Local Area Network (LAN) - A computer network confined to a small area like a home, school, or office building - Key Components: - Network Switch: Receives incoming data from one of its ports and redirects it to another port to its intended destination - NIC (Network Interface Card) is a network port used to attach a device to a network - CAN (Campus Area Network) - Connects LANs across a corporate of educational campus - Ex: University network connecting lecture halls, dorms, and libraries - WAN (Wide Area Network) - Spans large geographic areas, typically using leased telecommunication lines to interconnect LANs - Be familiar with various Network Topologies. - A diagram of computer network Description automatically generated OSI Model - pg.18 and Week2 PPT slides **Understand the functions and interactions of each layer:** - Application - Provides network services directly to end-users or applications, acting as the closest layer to the user - Categorized into 2 types: - User services: Programs like web browsers that interact with the user - System services: Utility programs that support system operations - HTTP, FTP, IRC, SSH, DNS - Presentation - Formats, compresses, and encrypts data so the receiving application can understand it - Examples: - Video Streaming: Video files are compressed at this layer to reduce buffering during playback - SSL/TSL Encryption: Ensures secure communication for web browsers by encrypting data before transmission - Session Layer - Establishes, manages, and terminates communication sessions between devices. It handles session management, synchronization, and data exchange coordination - This layer is responsible for setting up communication before data transfer begins and tearing down the session when it ends - Examples: - Video Conferencing: Synchronizing audio and video streams to ensure they remain in sync - File Transfers: Resuming interrupted downloads by maintaining the session state - Transport Layer - Ensures reliable, end-to-end communication between devices. It manages error correction, flow control, and the segmentation and reassembly of data - Examples: - TCP (Transmission Control Protocol): - Characteristics: Ensures reliable data delivery through connection-oriented communication - Example: Web browsing (HTTP/HTTPS), Email (SMTP, IMAP) - UDP (User Datagram Protocol): - Characteristics: Provides faster, connectionless communication without guaranteed delivery - Example: Video streaming, online gaming, VoIP (Voice over IP) - Network Layer - Responsible for logical addressing, translating IP addresses into physical addresses, and determining the best path for data to travel across a network. - Key Functions: - **Logical Addressing**: Uses IP addresses to uniquely identify devices on a network. - **Routing**: Determines the best path for data to reach its destination, often using routing protocols - **Packet Forwarding**: Handles the transfer of data packets between networks - Examples: - **IPv4 and IPv6:** The two versions of IP used to address devices - **Routing Protocols:** RIP, OSPF, EIGRP---used by routers to determine the best path - **BGP (Border Gateway Protocol):** Used for routing between autonomous systems on the internet - Data link Layer - Works with frames and is responsible for creating a reliable link between two directly connected nodes on the same network. - Key Functions: - **MAC Addressing**: The Data Link Layer assigns MAC (Media Access Control) addresses, which uniquely identify each device on a network. - **Frames**: This layer packages data into frames by adding a header and a trailer around the data packet. The frame is the complete message that travels over the physical network. - **Error Detection**: Ensures that the data arrives correctly, using techniques like checksums in the trailer. - Examples: - **Ethernet**: The most common Data Link Layer protocol, which uses MAC addresses to deliver frames - **Wi-Fi (802.11):** A wireless protocol that operates at this layer, managing connections between wireless devices - **Switches**: Networking devices that operate at Layer 2, using MAC addresses to forward frames between devices on the same network - Physical - Handles the transmission of raw data bits over a physical medium, such as cables or wireless signals - Key Functions: - **Transmission of Bits:** Manages the transmission of 0s and 1s as electrical voltage, light pulses, or radio waves. - **Physical Media:** Specifies the physical medium (cables, fiber optics, wireless) and how data is physically transmitted. - **Connector Types:** Details the connectors and interfaces, such as the type of connector (e.g., RJ-45) used to attach cables to network interfaces. - **Cabling Standards:** Defines standards like Cat 6, Cat 7 for Ethernet cables. - Examples: - Definition: Encoding is the process of converting digital data into signals that can be transmitted over a physical medium - Example: Representing data as electrical voltages or light pulses **Protocol Data Unit (PDU) (Module 2):** - Know the different types of the Protocol Data Units (PDU): Data/Payload, Segment, Packet, Frame. - Bit or symbol: The PDU for the physical layer, which deals with bits - Frame: The PDU for the data link layer, which prepares the PDU for local network - Packet: The PDU for the network layer - Segment: The PDU for the transport layer **Network Backbone Components:** - Know the roles of IDF, MDF, Cross Connects. - IDF - Serve as the spokes in the topology - Located in separate buildings or different floors - Provide local connectivity to end-user devices - Connect back to the MDF via fiber optic cables or high-speed Ethernet links - MDF - Acts as the central hub located in the main data center - Manages core routing and switching functions - Connects to external network (e.g., ISP) - Understand the function of a Entrance Facility/Demarc. **TCP/IP Suite:** - Collection of networking protocols that allow data to be transferred between devices on a network - TCP/IP basics: - TCP/IP is a set of rules and procedures that defines how data is exchanged over the internet. It's made up of multiple protocols, but 2 main ones are Transmission Control Protocol (TCP) and Internet Protocol (IP) - How TCP/IP works - Works by dividing data into packets, adding a destination address, and then passing the packets along the next protocol layer. TCP is responsible for ensuring the data is delivered to the correct destination in the correct order. IP is responsible for routing the packets to the correct destination **IPv4 and IPv6 Addressing (Module 3):** - Know the structure of an IPv4 and IPv6 address. - What's the purpose of Loopback, Broadcast, and APIPA addresses? **TCP Handshake:** - Be able to identify the TCP handshake process and understand its purpose. **MAC Address Structure (Module 3):** - Understand the MAC address composition, including OUI and serial number. - Organizational Unique Identifier - The first 24 bits identify the manufacturer and are assigned by the IEEE. - Example: 00:10:A4 represents the OUI in the MAC address. - Extension Identifier/Device ID - The remaining 24 bits serve as a unique identifier for the device, assigned by the manufacturer **Common Ports (Module 3):** - Know these common ports: 20, 21, 22, 53, 67, 80, 443, 3389. - 20 -- FTP-DATA, TCP, File Transfer \-\-- data - 21 -- FTP, TCP, File Transfer \-\-- control (an FTP server listens at port 21 and sends/receives data at port 20) - 22 -- SSH, TCP, Secure communications between Linux computers or, if installed, between Windows computers - 53 -- DNS, TCP or UDP, Name resolution - 67 -- DHCP, UDP, Distribution of IP addresses on a network -- client to server messages - 80 -- HTTP, TCP or UDP, Requests between web servers and web clients - 443 -- HTTPS, TCP, Secure communication between a web browser and a website - 3389 -- Remote Desktop Protocol (RDP), allows users to remotely access Windows computer or server **Network Troubleshooting tools/CMDs (Module 4)** **Know the purpose and basic use of these commands:** - ipconfig and parameters - ipconfig /release -- releases the current IP address lease from the DHCP server - ipconfig /renew -- Requests a new IP address lease from the DHCP server - ipconfig /flushdns -- Clears the DNS cache on your computer - ping -- troubleshoot connectivity, reachability, and name resolution - arp -- display the modify the Address Resolution Protocol (ARP) cache - nslookup -- helps find a particular domain name's IP address or a domain name system record **Purpose and features**: - DHCP - Dynamic Host Configuration Protocol (DHCP) is a network service that automatically assigns IP addresses and configuration information to devices. Key features include: - Centralized Management: Allows network administrators to manage and automate IP address assignments. - Reduced Configuration Errors: Minimizes manual setup for each device. - Efficient IP Handling: Recycles unused IP addresses for new devices. - Central Database: Maintains a record of connected devices to prevent duplicate assignments. - Guest Networks: Provides temporary IP addresses for visitors, simplifying access. - Mobile User Support: Enables users to switch networks without manual IP reconfiguration. - Lease Management: Assigns IP addresses for a limited time; clients must renew leases to retain their IP. - DHCP is built on the Bootstrap Protocol (BOOTP), an IETF standard. - DNS (PPT Slides) - Resource Records in a DNS Database - A Record - Maps hostnames to IPv4 addresses - AAAA Record - Maps hostnames to IPv6 addresses - MX Record - Mail server information **TCP and UDP (Module 4):** **Know the responsibilities of this protocols:** - TCP vs UDP protocol - TCP: Secure delivery like registered mail, every piece checked - Reliable: Ensures data arrives complete and in order. - Slower: Handshakes and error checks add overhead. - **Examples**: Web browsing, file transfers, emails. - UDP: Quick deliveries without error checking the data - Fast: No handshakes, ideal for real-time data like video/audio. - Less Reliable: Some packets might get lost, but speed is prioritized. - **Examples**: Streaming, gaming, online calls. - - Understand ICMP and ARP, including ARP broadcasts. - What is an ARP broadcast? - A message sent to all devices on a local network to request the MAC address associated with a specific IP address - What does the destination MAC look like for an ARP broadcast? - For an ARP broadcast, the destination MAC address is always "ff:ff:ff:ff:ff:ff", which represents a broadcast address, meaning the packet will be sent to every device on the local network - HTTP vs HTTPS - For HTTPS traffic, the domain name missouristate.edu will not appear in plaintext outside of the initial DNS query because the actual HTTP request will be encrypted. For HTTPS traffic, you would have to rely on IP addresses, or use the Server Name Indication (SNI) - POP3 vs IMAP4 vs SMTP - POP3 retrieves emails from a server to a device, downloading all emails at once and deleting them from the server. This is ideal for offline access but risks data loss without backups. It's less flexible than IMAP due to its age. - IMAP synchronizes emails across multiple devices, keeping them stored on the server. It allows for organization within the server mailbox, making it suitable for users accessing email from various devices. IMAP can be slower if downloading all messages but faster when retrieving only parts of them. - SMTP is the standard protocol for sending emails from a sender\'s device to a receiver\'s mailbox, facilitating the transfer of information between servers. - RDP - Remote desktop protocol - SSH - Secure Shell - SSH is a network protocol that enables secure access to a computer over an unsecured network, using cryptography for encryption and authentication. It\'s commonly used for remote server control, infrastructure management, and file transfers. - Operating on a client-server model, the SSH client connects to the SSH server, verifying its identity with public key cryptography. - Key Features of SSH: - Tunneling: Allows data packets to traverse restricted networks. - Terminal Access: Provides a secure, encrypted connection between two hosts. - File Transfers: Supports file transfer via SSH File Transfer Protocol (SFTP) or Secure Copy Protocol (SCP). - Graphical Applications: Enables secure execution of graphical X11 applications from remote locations - SSH is crucial for maintaining system security, facilitating safe access and management of networked systems.Telnet **Cable transmission flaws (Module 5):** Recognize the causes and effects of Attenuation, Latency, and Crosstalk: - Attenuation - loss of a signal's strength as it travels away from the source - Latency - delay between signal transmission and receipt - CrossTalk - occurs when the signal on one wire infringes on an adjacent wire signal **Transmission characteristics:** Understand the concepts of Frequency, Bandwidth, and Throughput: - **Frequency** - measured in MHz or GHz, indicates the number of times in a second that an electrical signal can change states. (Refers to going from 1 to 0 and back.) - **Bandwidth** is the amount of data in theory that can be transmitted - **Throughput** is the measure of how much data is actually transmitted. **Testing Processes:** Know the functionality and usage of iPerf3, including client/server commands. **Types of Network Cables (Copper/Fiber):** - Know the differences between Cat6, MMF, SMF, UTP, and STP. - Cat6 - A copper cable standard for high-speed Ethernet connections, categorized by performance levels. - MMF (Multimode Fiber) - A fiber optic cable allowing multiple light signals to travel simultaneously, suitable for shorter distances - SMF (Single-Mode Fiber) - A fiber optic cable designed for long-distance data transmission, allowing only one light signal through the core. - UTP (Unshielded Twisted Pair) - A copper cable with twisted wires and no shielding, used in low electromagnetic interference environments. - STP (Shielded Twisted Pair) - A copper cable with twisted pairs wrapped in shielding, providing better protection against electromagnetic interference than UTP. - Familiarize yourself with common fiber connectors: LC (local connector) and ST (straight tip). What's the purpose of Power over ethernet (POE)? - Delivers both data and power to devices over a single Ethernet cable, eliminating the need for separate power supplies and outlets Fiber standards: - MMF vs SMF - SMF - consists of a narrow core, it reflects little, the light does not disperse as the signal travels along the fiber. This continuity allows SMF to accommodate the highest bandwidths and longest distances. - MMF -- Larger core, light source travel at various angles, signals traveling over multimode fiber experience greater attenuation than those traversing single mode fiber. MMF is less expensive to install TIA/EIA-568B standards - \*\*Color coding - The TIA/EIA-568B color code specifies the wiring colors for RJ45 connectors: 1\. White/Orange 2\. Orange 3\. White/Green 4\. Blue 5\. White/Blue 6\. Green 7\. White/Brown 8\. Brown - This standard is used for all commercial and residential wiring in the US and helps prevent wiring errors. It also sets minimum requirements for cabling types; for instance, Category 5e cables support speeds up to 100 MHz and are compatible with 10BASE-T, Fast Ethernet, and Gigabit Ethernet.