Basic Cisco Router Security

You can access a Cisco router in many 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 and SSH access. With certain models, accessing the router is provided via a web interface using HTTP or HTTPS.

If you do not have physical access to a router via console or aux, 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.