A network administrator is verifying SSH remote access on a newly deployed enterprise switch named Dist-SW2. The hostname and IP domain name have been configured, and the administrator generated host keys using the CLI command `crypto key generate rsa modulus 512`. When administrative users attempt to establish remote sessions using SSH version 2, the connections fail. When the administrator executes the `show ip ssh` command on Dist-SW2 to inspect the SSH operational state, which status line is displayed in the output?
- SSH Enabled - version 1.5Cevap
- BSSH Enabled - version 2.0
- CSSH Disabled - invalid key length
- DSSH Enabled - version 1.99
Cevap
The switch displays 'SSH Enabled - version 1.5' because the generated RSA key modulus is 512 bits, which falls below the 768-bit threshold required for SSH version 2.
In Cisco IOS, SSH version 2 requires an RSA key pair with a minimum modulus size of 768 bits (1024 bits or higher is recommended). When an administrator generates an RSA key with a modulus of 512 bits, Cisco IOS successfully creates the key but defaults the SSH daemon to SSH version 1.5. Consequently, running `show ip ssh` displays 'SSH Enabled - version 1.5', and clients attempting to connect strictly using SSH v2 will be rejected.
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Anahtar Kavram
SSH Version and RSA Key Modulus Requirements