2.5. Using Telnet

Function Introduction

Telnet is a network protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communications facility using a virtual terminal connection. User data is interspersed in-band with Telnet control information in an 8-bit byte oriented data connection over the Transmission Control Protocol (TCP). Telnet was developed in 1969 beginning with RFC 15, extended in RFC 854, and standardized as Internet Engineering Task Force (IETF) Internet Standard STD 8, one of the first Internet standards. Historically, Telnet provided access to a command-line interface (usually, of an operating system) on a remote host. Most network equipment and operating systems with a TCP/IP stack support a Telnet service for remote configuration (including systems based on Windows NT). Because of security issues with Telnet, its use for this purpose has waned in favor of SSH.

Principle Description

N/A

Telnet another device with network port

Switch# telnet 10.10.29.247
Entering character mode
Escape character is '^]'.
Switch#

Switch# telnet 2001:1000::71
Entering character mode
Escape character is '^]'.
Switch#

Telnet another device with management port

Switch# telnet mgmt-if 10.10.29.247
Entering character mode
Escape character is '^]'.
Switch#

Switch# telnet mgmt-if 2001:1000::2
Entering character mode
Escape character is '^]'.
Switch#

Configure telnet server

Switch# configure terminal

Switch(config)# service telnet enable

Switch(config)# exit