Which configuration must be set before generating an RSA key pair for SSH on a router?

Before generating an RSA key pair for SSH on a Cisco router, you must assign a DNS domain name using the ip domain-name command. This is a prerequisite because the router uses the combination of its hostname and the domain name to create a fully qualified domain name (FQDN), which is then used as part of the key generation process. Without a domain name, the router cannot generate the necessary cryptographic keys for SSH. While configuring VTY access, specifying the SSH version, and creating a user with a password are all essential steps for enabling and securing SSH, they are not required before the RSA key pair generation itself. The key generation is a foundational cryptographic step that depends on the router's identity, established by the hostname and domain name.