security risk by using telnet session to routers

[henry_banh]

A question regarding security issue when I use a telnet session to my routers. How can I prevent from capturing my keystrokes ( using sniffer

software) when I telnet to the routers.

Thank for your help.

[johturner]

Use SSH (Secure Shell) You will need to make sure that the router you are using supports it. At least ipsec 12.05(s) on 7200 and 7500 routers. You will also need client software that supports ssh.

ssh router config:

crypto key generate rsa

ip ssh time-out 60

ip ssh authentication-retries 5

The number of ssh connections is limited to the number of vty ports

Use "clear crypto key" or "no crypto key" to disable.

[heyligerb]

Either Use SSH as noted before or run IP Sec between you and the router (the strength of this depends on you topology) or last you can implement Kerberos and execute a kerberized telnet session (40 bit encryption)

Brian Heyliger