Skip to content

title: Networking description: Networking fundamentals for sysadmins — the OS-agnostic foundation: how networks work, the OSI/TCP-IP models, IP addressing and subnetting, TCP/UDP and ports, DNS and DHCP, switching and VLANs, routing and NAT.

Networking Fundamentals

Networking is the foundation under every other track — Linux, Windows, hosting, and cloud all run on it. These concepts are OS-agnostic: learn them once and they apply everywhere. Work through them in order if networking is new to you.

Guides

  1. What Is a Network? — clients/servers, LAN/WAN, packets, and the devices involved
  2. The OSI and TCP/IP Models — the layered models and how to troubleshoot with them
  3. IP Addressing and Subnetting — IPv4, CIDR, subnet math, private ranges, IPv6 intro
  4. TCP, UDP, and Ports — the transport layer, the 3-way handshake, and well-known ports
  5. DNS and DHCP — name resolution and automatic IP assignment
  6. Switching and VLANs — Layer 2, MAC addresses, and network segmentation
  7. Routing and NAT — moving between networks and sharing public IPs

Pairs with the Linux track

Once you understand the concepts here, the Linux networking guides show you how to configure and inspect them on a real server.