- The data transferred betweenthe system is in Plain text form and is not in encrypted format which is the major security Concern so, the data can easily read by anybody in the network and hack the system.

- Telnet is mostly used in Private network as it's highely insecure to use in public.

- Telnet does not use Authentication which is again a security issue.

- Telnet runs on port no 23.

Configuration of Telnet
#Line vty 4
#password "abc"


- SSH stands for Secure Shell and it is now only major protocol to access the network devices and servers over internet.

- SSh encrypts the dada being transferred between the syatem so it cannot be decode by hackers.

- SSh also uses a public key for the authentication of users accessing a server and it is a great practise providing Security.

- SSh runs on port no. 22.

Configuration of Telnet
#ip domain name "cisco"
#crypto key generate rsa
#1024 ("Preferred value")
#username "admin" password "password"
#line vty 4
#transport input ssh
#login local