CCIE Security Exam Certification Guide

Basic Security on Cisco Routers

You can access a Cisco router in a number of ways. You can physically access a router through the console port, or you can access a router remotely through a modem via the auxiliary port. You can also access a router through a network or virtual terminal ports (VTY lines), which allow remote Telnet access.

If you do not have physical access to a router—either through a console port or an auxiliary port via dialup—you can access a router through the software interface, called the virtual terminal (also referred to as a VTY port). When you telnet to a router, you might be required to enter the VTY password set by the network administrator. For example, on Router R1, the administrator types R2's remote address and ...