Cisco Hardware Overview

Components of a Cisco router include RAM, NVRAM, CPU, flash, ROM, configuration registers, interfaces, ASICs, and so on.

The RAM stores current configuration files and other important information, such as Cisco Express Forwarding (CEF) tables. In addition, it also stores IP routing tables and buffer information. The routing-protocol processes run in RAM (Border Gateway Protocol [BGP], Open Shortest Path First Protocol [OSPF] and so forth). Information in the RAM is lost if the router is power cycled or restarted. You can view the current configuration of a router by using the command show running-config or write terminal.