NetworkInterfaces

NetworkInterfaces are the endpoints a device uses to participate in a network. They can be physical NICs such as Ethernet or Wi‑Fi, or virtual interfaces such as loopback, VPN tunnels, or container adapters. Each interface has a name, a hardware address (MAC in most cases), and an IP assignment (IPv4 and/or IPv6). A device may have several interfaces to connect to different networks or to separate traffic types.

Key properties include the interface name, MAC address, assigned IP addresses and prefixes, MTU, and operational state (up or down). Other commonly exposed data are speed, duplex, link status, and usage statistics. Names depend on OS conventions (for example Linux often uses enpXsY or ethX, wlanX; loopback is lo).

Management and configuration are performed with system tools. IP addressing can be dynamic via DHCP or static. Linux tools include the ip command and, for legacy systems, ifconfig, along with configuration frameworks such as Netplan or NetworkManager; Windows uses netsh and PowerShell; macOS uses networksetup. Interfaces participate in routing by binding routes and default gateways to a specific interface.

Virtual and advanced interfaces extend networking options. VLANs use 802.1Q tagging; virtual interfaces (tun/tap, veth) support VPNs and containers; bonding or bridging aggregates interfaces or connects them at the data-link layer to form larger networks.

Security and troubleshooting considerations include correct IP configuration, avoiding conflicts, verifying link status, and reviewing firewall rules and NAT settings that apply to each interface. Common issues include no link, misconfigured addresses, or routing problems, diagnosed via interface state checks, connectivity tests, and routing table inspection.