Configuring The Ssh Settings - SMC Networks 8124PL2 - annexe 1 Management Manual

Configuring the Switch
6. Enable SSH Service – On the SSH Settings page, enable the SSH server on
the switch.
7. Challenge-Response 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. The following exchanges take
place during this process:
1. The client sends its public key to the switch.
2. The switch compares the client's public key to those stored in memory.
3. If a match is found, the switch uses the public key to encrypt a random
sequence of bytes, and sends this string to the client.
4. The client uses its private key to decrypt the bytes, and sends the decrypted
bytes back to the switch.
5. The switch compares the decrypted bytes to the original bytes it sent. If the two
sets match, this means that the client's private key corresponds to an
authorized public key, and the client is authenticated.
Notes: 1.
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.
2.
The SSH server supports up to four client sessions. The maximum number
of client sessions includes both current Telnet sessions and SSH sessions.

Configuring the SSH settings

The SSH server includes basic settings for authentication.
Field Attributes
• SSH Server Status – Allows you to enable/disable the SSH server on the switch.
(Default: Disabled)
• Version – The Secure Shell version number. Version 2.0 is displayed, but the
switch supports management access via either SSH Version 1.5 or 2.0 clients.
• SSH Authentication Timeout – Specifies the time interval in seconds that the
SSH server waits for a response from a client during an authentication attempt.
(Range: 1 to 120 seconds; Default: 120 seconds)
• SSH Authentication Retries – Specifies the number of authentication attempts
that a client is allowed before authentication fails and the client has to restart the
authentication process.
(Range: 1-5 times; Default: 3)
• SSH Server-Key Size – Specifies the SSH server key size.
(Range: 512-896 bits; Default:768)
• The server key is a private key that is never shared outside the switch.
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