.. include:: global.rst ******************************************************** Chapter 3: Common Network Toplogies and Infrastructures ******************************************************** Network Topologies ------------------ Star Topology ^^^^^^^^^^^^^ - All devices connect to a central switch or hub - Traffic flows through the central device - Easy to manage and troubleshoot - Vulnerability: failure of the central device affects the entire network Bus Topology ^^^^^^^^^^^^ - All devices share a single communication line - Simple and low cost - Traffic collisions increase as more devices are added - Vulnerability: break in the main cable disrupts all devices Mesh Topology ^^^^^^^^^^^^^ - Devices connect to multiple or all other devices - High redundancy and fault tolerance - Complex and expensive to implement - Common in mission-critical networks IP and MAC Addresses -------------------- IP Address ^^^^^^^^^^ - Logical address assigned to a device - Used to identify devices across networks - Commonly viewed using ``ipconfig`` and tested with ``ping`` MAC Address ^^^^^^^^^^^ - Physical hardware address of a network interface - Used for local network communication - Mapped to IP addresses using ``arp`` De-Militarized Zone (DMZ) -------------------------- - Network segment exposed to external traffic - Hosts public-facing services such as web or DNS servers - Separated from the internal network by firewalls - Traffic is tightly controlled and monitored - Common focus during firewall and service analysis Network Devices --------------- Switch ^^^^^^ - Connects devices within the same local network - Uses MAC addresses to forward frames Router ^^^^^^ - Connects multiple networks together - Routes traffic using IP addresses - Often performs NAT and subnetting Firewall ^^^^^^^^ - Filters traffic based on security rules - Protects internal networks from unauthorized access - Controls access to the DMZ Key Concepts ------------ - Subnetting: dividing networks into smaller logical segments - Logical Topology: how data flows through a network - Client/Server Networks: centralized servers provide services to clients Purpose of This Chapter ----------------------- This chapter explains why tools like Zenmap and Wireshark are used to analyze network structure, traffic flow, and exposed services in virtual environments.