Telnet

The following five commands all achieve the same resultthe attempt to connect remotely to the router named paris at IP address 172.16.20.1.

Denver>telnet paris	Enter if ip host command was used previously to create a mapping of an IP address to the word paris
Denver>telnet 172.16.20.1
Denver>paris	Enter if ip host command is using default port #
Denver>connect paris
Denver>172.16.20.1

Any of the preceding commands lead to the following configuration sequence:

Paris>	As long as vty password is set. See Caution following this table
Paris>exit	Terminates the Telnet session
Denver>
Paris>logout	Terminates the Telnet session
Denver>
Paris>, release, then press	Suspends the Telnet session, but does not terminate it
Denver>
Denver>	Resumes the connection to paris
Paris>
Denver>resume	Resumes the connection to paris
Paris>
Denver>disconnect paris	Terminates the session to paris
Denver>
Denver#show sessions	Displays connections you opened to other sites
Denver#show users	Displays who is connected remotely to you
Denver#clear line x	Disconnects remote user connected to you on line x
	Line number is listed in the output gained from the show users command
Denver(config)#line vty 0 4
Denver(config-line) session-limit x	Limits the number of simultaneous sessions per vty line to x amount

Caution:

The following configuration creates a big security hole. Never use it in a live production environment. Use it in the lab only!

Denver(config)#line vty 0 4	.
Denver(config-line)#no password	Remote user is not challenged when Telnetting to this device
Denver(config-line)#no login	Remote user moves straight to user mode

Caution:

A device must have two passwords for a remote user to be able to make changes to your configuration:

• Line vty password (or have it explicitly turned off; see previous Caution)

• Enable or enable secret password

Without the enable or enable secret password, a remote user will only be able to get to user mode, not to privileged mode. This is extra security.