Configuring Secure Shell (SSH)
Prerequisite for Using SSH
■ PEM (Privacy Enhanced Mode): Refers to an ASCII-formatted client
public-key that has been encoded for portability and efficiency.
SSHv2 client public-keys are typically stored in the PEM format. See
figures
4-3 and 4-4 for examples of PEM-encoded ASCII and non
encoded ASCII keys.
■ Private Key: An internally generated key used in the authentication
process. A private key generated by the switch is not accessible for
viewing or copying. A private key generated by an SSH client applica-
tion is typically stored in a file on the client device and, together with
its public key counterpart, can be copied and stored on multiple
devices.
■ Public Key: An internally generated counterpart to a private key. A
device’s public key is used to authenticate the device to other devices.
■ Enable Level: Manager privileges on the switch.
■ Login Level: Operator privileges on the switch.
■ Local password or username: A Manager-level or Operator-level
password configured in the switch.
■ SSH Enabled: (1) A public/private key pair has been generated on
the switch (crypto key generate ssh [rsa]) and (2) SSH is enabled (ip
ssh). (You can generate a key pair without enabling SSH, but you
cannot enable SSH without first generating a key pair. See
“2. Gener-
ating the Switch’s Public and Private Key Pair” on page 4-10 and “4.
Enabling SSH on the Switch and Anticipating SSH Client Contact
Behavior” on page 4-15.)
Prerequisite for Using SSH
Before using the switch as an SSH server, you must install a publicly or
commercially available SSH client application on the computer(s) you use for
management access to the switch. If you want client public-key authentication
(page
4-2), then the client program must have the capability to generate or
import keys.
4-4
