CLI Reference Guide-R02

Chapter 8 | Authentication Commands
Secure Shell
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3. Import Client’s Public Key to the Switch – Use the copy tftp public-key
command to copy a file containing the public key for all the SSH client’s
granted management access to the switch. (Note that these clients must be
configured locally on the switch with the username command.) The clients are
subsequently authenticated using these keys. The current firmware only
accepts public key files based on standard UNIX format as shown in the
following example for an RSA key:
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steve@192.168.1.19
4. Set the Optional Parameters – Set other optional parameters, including the
authentication timeout and the number of retries.
5. Enable SSH Service – Use the ip ssh server command to enable the SSH server
on the switch.
6. Authentication – One of the following authentication methods is employed:
Password Authentication (for SSH V2 Clients)
a. The client sends its password to the server.
b. The switch compares the client's password to those stored in memory.
c. If a match is found, the connection is allowed.
Note: To use SSH with only password authentication, the host public key must still
be given to the client, either during initial connection or manually entered into the
known host file. However, you do not need to configure the client's keys.
Public Key Authentication – When an SSH client attempts to contact the switch,
the SSH server uses the host key pair to negotiate a session key and encryption
method. Only clients that have a private key corresponding to the public keys
stored on the switch can access it. The following exchanges take place during
this process:
Authenticating SSH v2 Clients
a. The client first queries the switch to determine if public key
authentication using a preferred algorithm is acceptable.
b. If the specified algorithm is supported by the switch, it notifies the
client to proceed with the authentication process. Otherwise, it
rejects the request.