📡Systems Approach to Computer Networks Unit 11 – Internet Protocol (IP) Fundamentals

What's IP and Why Should I Care?

• IP (Internet Protocol) is the fundamental protocol that enables communication between devices on the internet
• Provides a standardized way for devices to send and receive data packets across networks
• Enables devices with different hardware and software to communicate seamlessly
• Allows for scalability and flexibility in network design and implementation
• Forms the foundation for higher-level protocols like TCP, UDP, and HTTP
• Understanding IP is crucial for network administrators, developers, and cybersecurity professionals
  • Helps in designing efficient and secure networks
  • Enables troubleshooting and problem-solving in case of network issues

IP Addresses: The Internet's Phone Numbers

• IP addresses are unique identifiers assigned to each device connected to a network
• Consist of a series of numbers separated by dots (IPv4) or hexadecimal numbers separated by colons (IPv6)
• IPv4 addresses are 32 bits long and are divided into four 8-bit sections (192.168.0.1)
• IPv6 addresses are 128 bits long and are divided into eight 16-bit sections (2001:0db8:85a3:0000:0000:8a2e:0370:7334)
• IP addresses are used to route data packets between devices on a network
• Can be static (manually assigned) or dynamic (automatically assigned by DHCP)
• Public IP addresses are globally unique and assigned by ISPs
  • Used for communication over the internet
• Private IP addresses are used within local networks and are not globally unique (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)

Packet Party: How IP Moves Data

• IP uses a packet-switching approach to move data across networks
• Data is divided into smaller chunks called packets
• Each packet contains a header with source and destination IP addresses, protocol information, and other metadata
• Packets are independently routed through the network based on their destination IP address
• Routers and switches use routing tables to determine the best path for each packet
• Packets may take different routes to reach their destination, depending on network conditions
  • This allows for fault tolerance and load balancing
• At the destination, packets are reassembled in the correct order to reconstruct the original data

Subnetting: Slicing Up the IP Pie

• Subnetting is the process of dividing a larger network into smaller subnetworks (subnets)
• Helps in organizing and managing large networks more efficiently
• Subnets are created by borrowing bits from the host portion of an IP address to create a subnet mask
• Subnet masks determine which part of an IP address represents the network and which part represents the host
• Subnetting allows for better network performance, security, and scalability
  • Reduces network congestion by localizing traffic within subnets
  • Enables access control and security policies to be applied at the subnet level
• CIDR (Classless Inter-Domain Routing) notation is used to represent subnets (192.168.0.0/24)

Routing: Getting Packets from A to B

• Routing is the process of forwarding packets between networks to reach their destination
• Routers use routing tables to determine the best path for each packet based on its destination IP address
• Routing tables contain information about directly connected networks and learned routes from other routers
• Routers exchange routing information using routing protocols like OSPF, EIGRP, and BGP
  • These protocols help routers learn about network topology and maintain up-to-date routing tables
• Routing decisions are based on factors like network prefix, metric, and administrative distance
• Static routing involves manually configuring routes in the routing table
• Dynamic routing uses routing protocols to automatically learn and update routes based on network changes

IP Versions: The Old and the New

• There are two main versions of IP: IPv4 and IPv6
• IPv4 is the original version and is still widely used today
  • Uses 32-bit addresses, allowing for approximately 4.3 billion unique addresses
  • Address exhaustion has led to the need for techniques like NAT (Network Address Translation)
• IPv6 is the newer version, designed to address the limitations of IPv4
  • Uses 128-bit addresses, providing a vastly larger address space (approximately 340 undecillion addresses)
  • Includes built-in support for security (IPsec) and quality of service (QoS)
  • Simplifies header structure and eliminates the need for NAT
• Transition mechanisms like dual-stack, tunneling, and translation allow for coexistence and gradual migration from IPv4 to IPv6

Common IP Protocols and Their Roles

• IP is the foundation for many higher-level protocols that enable various network services
• TCP (Transmission Control Protocol) provides reliable, connection-oriented data delivery
  • Used for applications that require data integrity and ordered delivery (HTTP, FTP, email)
• UDP (User Datagram Protocol) provides unreliable, connectionless data delivery
  • Used for applications that prioritize speed over reliability (DNS, VoIP, streaming)
• ICMP (Internet Control Message Protocol) is used for diagnostic and error reporting purposes
  • Ping and traceroute utilities rely on ICMP messages
• DHCP (Dynamic Host Configuration Protocol) automates the assignment of IP addresses and other network configuration parameters to devices
• DNS (Domain Name System) translates human-readable domain names to IP addresses
• ARP (Address Resolution Protocol) maps IP addresses to MAC addresses within a local network

Real-World IP: Practical Applications and Issues

• IP is the backbone of the modern internet and enables countless applications and services
  • Web browsing, email, instant messaging, video conferencing, and more
• IP-based networks are used in various settings, including homes, offices, data centers, and mobile networks
• Network administrators use tools like packet analyzers and network monitoring systems to troubleshoot and optimize IP networks
• Cybersecurity professionals deal with IP-related threats like DDoS attacks, IP spoofing, and network intrusions
• IP addressing and subnetting are crucial skills for designing and managing scalable and secure networks
• The transition from IPv4 to IPv6 poses challenges and opportunities for organizations worldwide
  • Requires careful planning, testing, and implementation to ensure compatibility and performance
• Emerging technologies like IoT, 5G, and edge computing rely heavily on IP for connectivity and data exchange