Cisco Certified Network Associate (CCNA) Practice Exam

Which command generates RSA keys for SSH?

1. (config)#crypto key generate rsa modulus 1024

2. (config)#ssh key generate rsa 1024

3. (config)#crypto generate rsa

4. (config)#generate rsa modulus 1024

The correct answer is: (config)#crypto key generate rsa modulus 1024

The command that successfully generates RSA keys for SSH is indeed "crypto key generate rsa modulus 1024". This command is part of the Cisco IOS command-line interface and is specifically designed for creating RSA key pairs that are used for secure SSH communication. When using this command, the "crypto key generate rsa" portion indicates that you are invoking the cryptographic function to generate RSA keys. The "modulus 1024" specifies the size of the key; in this case, a 1024-bit key is being generated, which is generally considered secure for SSH communications. The size of the modulus is crucial because it directly impacts the strength of the encryption; a larger modulus would provide stronger security but would require more processing power. Other options do not conform to the valid syntax and functionality required for generating RSA keys in the Cisco environment. For instance, "ssh key generate rsa 1024" and "generate rsa modulus 1024" do not represent recognized commands in Cisco IOS. The "crypto generate rsa" is not complete as it lacks the key size specification and will not function as intended.