Tags:Cisco config ios router Secure Shell(SSH) Security ssh switch telnet
Using Telnet for remote administration of Cisco Routers and Switches (infact for any other device like a unix,linux or a solaris seerver) is not very secure as the data including the passwords are sent in clear text. It will only be a matter of time for a malicous attacker who can sniff the packets to gain access to the passwords and infact the whole network.
It is recommended that Secure Shell (SSH) is used for remote administration of Cisco Routers and Switches.
NOTE: Cisco IOS on the Catalyst switches are by default supplied with the SSH feature bultin. However, the basic Cisco IOS for the routers do not have the SSH facility built-in. To use the SSH feature on Cisco Routers, you need to have the Cisco IOS version with the IPSec(DES or 3DES) encryption software.