To configure SSH access, and disable Telnet, follow these steps.

1. Enable the new AAA model and configure a user account and optional enable password:

   aaa new-model
   username cisco secret 0 cisco
   enable secret 0 cisco

2. Generate SSH keys and set up time-out and other parameters:

   ip domain name some-domain.com
   crypto key generate rsa
   ip ssh version 2
   ip ssh time-out 60
   ip ssh authentication-retries 2

   When generating SSH keys, you first need to specify a domain name. You will also be prompted to enter the modulus bit rate. Although 1024 is suggested, it is recommended to set it to 2048 as lower is deprecated.
3. Optionally, to disable Telent access, explicitly set the transport:

   line vty 0 4
   transport input ssh