Executing IP SSH does not enable SSH on the switch

The switch does not have a host key. Verify by executing show ip host-public-key. If you see the message

ssh cannot be enabled until a host key is configured (use 'crypto' command).

you need to generate an SSH key pair for the switch. To do so, execute crypto key generate (see "Generating the switch's public and private key pair" in the SSH chapter of the access security guide for your switch.)