LANs

A local area network (LAN) is a computer network that interconnects devices within a limited geographic area, such as a home, office, or campus. LANs enable resource sharing (printers, files, applications) and communication among users and devices. They are typically privately owned, operated, and administered by an organization or household, with network boundaries defined by internal switches and routers.

Wired LANs commonly use Ethernet (IEEE 802.3) with copper or fiber. Speeds range from 10 Mbps in early deployments to 100 Mbps, 1 Gbps, 10 Gbps, and higher. Wireless LANs (WLANs) use IEEE 802.11 standards, providing mobility via access points that connect wireless clients to the wired LAN. Modern WLANs can deliver multi-gigabit aggregate bandwidth with proper spectrum management.

Topology is typically a star, with devices connected to central switches. Hubs are largely obsolete. A switch forwards frames by MAC address; a router links the LAN to other networks. VLANs can segment traffic for security or performance.

LAN management usually includes DHCP for IP addressing, DNS for name resolution, and services such as file sharing and printer sharing. Security features include access control, firewalls, and encryption for wireless links (WPA2/WPA3). QoS can prioritize latency-sensitive traffic.

LANs range from small home networks to large corporate campuses. Performance depends on cabling, switches, and device count, while administration covers capacity planning, security hardening, and software updates.