Routers: The IOS and Its User Interface
Before examining the IOS, a review of hardware and hardware terminology is useful. This
section of the book reviews common hardware details.
Most Cisco routers have a console and an auxiliary port. All Cisco routers have a console port,
which is meant for local administrative access, from an ASCII terminal or computer using a
terminal emulator. The auxiliary port, missing on a few models of Cisco routers, is intended for
asynchronous dial access from an ASCII terminal or terminal emulator; the auxiliary port is
often used for dial backup.
Each router has different types of memory as follows: