ECS4100 Series CLI Reference Guide-R07

Chapter 8 | Authentication Commands
Secure Shell
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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.
c. The client sends a signature generated using the private key to the
switch.
d. When the server receives this message, it checks whether the
supplied key is acceptable for authentication, and if so, it then checks
whether the signature is correct. If both checks succeed, the client is
authenticated.
Note: The SSH server supports up to eight client sessions. The maximum number
of client sessions includes both current Telnet sessions and SSH sessions.
Note: The SSH server can be accessed using any configured IPv4 or IPv6 interface
address on the switch.
ip ssh
authentication-retries
This command configures the number of times the SSH server attempts to
reauthenticate a user. Use the no form to restore the default setting.
Syntax
ip ssh authentication-retries count
no ip ssh authentication-retries
count – The number of authentication attempts permitted after which the
interface is reset. (Range: 1-5)
Default Setting
3
Command Mode
Global Configuration
Example
Console(config)#ip ssh authentication-retires 2
Console(config)#