Exploring routing concepts

Routers are Layer 3 devices that operate at the Network layer of the Open Systems Interconnection (OSI) and the Internet layer of the Transmission Control Protocol/Internet Protocol (TCP/IP) networking models. Routers are one of the most essential networking devices found within private and public networks as they allow network professionals to interconnect two or more different networks together, and forward packets to their destinations. For instance, routers can interconnect different IP subnets, allowing devices on one IP network to communicate with hosts on another IP network and interconnect networks with different media types, such as an Ethernet network with a fiber optic.

Routers are built to perform many Layer 3 operations such as Network Address Translation (NAT) and filtering traffic using Access Control Lists (ACLs). Some routers even support Virtual Private Network (VPN) capabilities, allowing network professionals to set up site-to-site...