Chapter 4: Basic Net working

Responsibilities of SIS Admins for Networking

  • Administrators may be tasked with networking responsibilities in various roles.

  • Familiarity with multiple networking technologies is essential.

Networking Certifications

  • CompTIA Network+ Certification

    • Recommended for entry-level networking roles.

  • Cisco Certifications

    • CCNA (Cisco Certified Network Associate): Deeper knowledge of networking.

    • CCNP (Cisco Certified Network Professional): Advanced certification beyond CCNA.

  • Other certifications available, but CompTIA and Cisco are the most recognized in the industry and by governments for networking roles.

Key Networking Components

  • Routers, Switches, Firewalls

    • Essential devices for data transport.

  • Common Network Ports

    • SMTP (Simple Mail Transfer Protocol): Port 25

    • HTTPS (Secure HTTP): Port 443

OSI Model Layers

  • The OSI (Open Systems Interconnection) model consists of seven layers through which data travels:

    • Layer 1 - Physical Layer: Cabling, network cards.

    • Layer 2 - Data Link Layer: Frames and media access control (MAC) addresses.

    • Layer 3 - Network Layer: IP addressing and routing between networks.

    • Layer 4 - Transport Layer: Protocols like TCP and UDP, ports.

    • Layer 5 - Session Layer: Management of sessions and communication flow.

    • Layer 6 - Presentation Layer: Data format translation and encryption in VPNs.

    • Layer 7 - Application Layer: End-user applications such as web browsers, email clients.

IP Addressing

  • IPv4

    • Currently the most commonly used version of Internet Protocol.

    • Uses 32-bit addressing, allowing for over 4 billion unique addresses.

  • IPv6

    • A newer version that will eventually replace IPv4.

  • Understanding of:

    • Network Address Translation (NAT)

    • Subnetting

    • Dynamic IP Addressing

    • DNS (Domain Name System): Essential for translating domain names to IP addresses.

Directory Services

  • Example: Active Directory

    • Relies on DNS services.

Internet Service Provider (ISP) Products

  • Various connection types:

    • Wireless connections.

    • Layer 2 connections for remote offices.

    • MPLS (Multiprotocol Label Switching) & SD-WAN (Software-Defined Wide Area Network): Alternatives to traditional VPNs.

Virtual Private Networks (VPN) Setup

  • Learn to configure:

    • Client-to-Site Tunnels: Allows remote users to connect securely to a network.

    • Site-to-Site Tunnels: Connects two networks securely.

  • Consider balance between security and usability.

Networking Compliance Standards

  • Regulations vary by industry and country:

    • Sarbanes-Oxley and PCI Compliance for finance sectors.

    • HIPAA Compliance for healthcare sectors.

    • Other various compliance requirement based on sector.

  • Not all compliance is legally mandated; some are best practices.

Cabling Considerations

  • Adhere to laws regarding cabling installation—some cables require licensed professionals.

  • Familiarity with various cabling types:

    • Traditional Ethernet cables.

    • Fiber optic cables - increasingly used in servers and storage.

Wireless Networking

  • Importance of speed and security.

  • Keeping up to date with secure technologies necessary to mitigate risks of data breaches.

Internet Protocol Family

  • TCP/IP:

    • Acronym representing Transmission Control Protocol (TCP) and Internet Protocol (IP).

    • Analogy: IP as a car; TCP as the driver. They work together to transport data.

Key TCP/IP Protocols

  • TCP: Connection-oriented, ensures data delivery (ideal for banking and secure transactions).

  • UDP (User Datagram Protocol): Connectionless, faster, tolerates some data loss (ideal for gaming).

  • GRE (Generic Routing Encapsulation): Tunneling protocol for VPNs.

Networking Data Packet Journey

  • Path followed by data packets:

    • Starts at the source application (e.g., Word), edited and saved.

    • Proceed through processor and network card, out through network cables.

    • Leaves Local Area Network (LAN) and travels to destination (e.g., cloud storage).

    • Utilizes routers and switches; final stop at destination network firewall.

    • The journey can be observed using tools like Wireshark.

OSI Model as a Data Transmission Framework

  • Each layer in the OSI model has distinct functions and responsibilities.

  • Example of Layer functionality:

    • Layer 1 (Physical): Test using loopback (ping 127.0.0.1).

    • Layer 2 (Data Link): Frame and MAC addressing.

    • Layer 3 (Network): Routing and IP addressing—relates to routers.

    • Layer 4 (Transport): Protocols on top of IP (TCP, UDP).

    • Layer 5 (Session): Session coordination.

    • Layer 6 (Presentation): Data formatting and encryption.

    • Layer 7 (Application): User applications, e.g., web browsers.

IPv4 Addressing Details

  • Dotted Decimal Notation

    • Each IP address is composed of four octets separated by periods.

    • Example: 192.168.0.1

  • Octets: Represent values in binary format (8 bits each), capable of total of 256 (0-255) distinct values.

Understanding Binary and Decimal

  • Binary system: Values as combinations of 0 (off) and 1 (on).

    • Example: One in binary is 00000001.

  • Transition from binary to decimal for easier understanding (0-9 vs 0-255).

Routing Tools in Windows

  • Ping Command

    • Basic connectivity test.

    • Variations include:

    • ping -t: Continuous ping until stopped.

    • ping -l [size]: Adjust packet size to test maximum handling size.

  • ARP Command

    • Address Resolution Protocol allows the retrieval of IP-MAC mappings.

  • IP Config Command

    • Displays IP address, subnet mask, gateway and more.

    • ipconfig /all for comprehensive details.

  • Routing Command

    • Displays routing tables.

Traceroute and Pathping

  • Traceroute: Shows the path taken by packets to a destination.

  • Pathping: Combines ping and traceroute functionalities, providing route details and packet loss info.

Dynamic and Static Routing

  • Static Routing: Manually set routes for data forwarding.

  • Dynamic Routing: Utilizes protocols like RIP (Routing Information Protocol) for automatic route discovery and adjustments based on network changes.

  • Configuration Commands for different operating systems (e.g. Windows, Cisco, etc.) differ but aim to achieve the same goal of establishing routes.

VLANs as an Evolution in Networking

  • VLANs (Virtual Local Area Networks): Created to logically separate networks within a switch without needing physical segmentation.

  • Helps in traffic management, security, and efficient routing with added flexibility using Layer 3 switches.

Concluding Remarks

  • Knowledge of protocols, tools, compliance, and best practices is crucial for effective networking and administration in any organization. Stay updated on evolving technologies as networking continues to change rapidly.