Networking Basics: Switching, Routing, Gateways, and IP Forwarding (Linux)

Vocabulary flashcards covering key networking concepts and Linux commands used for configuring and troubleshooting basic network connectivity, routing, and IP forwarding.

IP address

A numeric label assigned to a host's network interface for identification and routing (e.g., 192.168.1.10/24).

Subnet

A distinct network segment defined by a network address and mask (e.g., 192.168.1.0/24).

CIDR notation

Classless Inter-Domain Routing prefix length used to denote subnet size (e.g., /24).

Gateway

The next-hop device (usually a router) that forwards traffic from a local network to other networks.

Router

A device that connects multiple networks and forwards packets between them via interfaces on each network.

Switch

A device that forwards frames within the same local network, enabling communication on a subnet.

Interface

A network connection on a Linux host (physical or virtual), such as eth0.

ip link

Linux command to list and manage network interfaces.

ip addr

Linux command to display the IP addresses assigned to interfaces.

ip addr add

Linux command to assign an IP address to an interface (temporary unless persisted).

ip route

Linux command to view the current IP routing table.

ip route add

Linux command to add a routing entry specifying a destination network and next-hop gateway.

Default route

A catch-all route (0.0.0.0/0) used when no more specific route exists, typically via a gateway.

192.168.1.1

Router's IP address on the 192.168.1.0/24 network; serves as the gateway for that network.

192.168.2.1

Router's IP address on the 192.168.2.0/24 network; serves as the gateway for that network.

192.168.1.0/24

Subnet for the 192.168.1.x network; addresses range within this block.

192.168.2.0/24

Subnet for the 192.168.2.x network; addresses range within this block.

IP Forwarding

The process of routing IP packets between different network interfaces, enabling a Linux host to act as a router.