3Com Switch 8800 Family Configuration Guide

SSH Terminal Service 773
Generating or destroying an RSA key pair
Use this configuration task to generate or destroy an RSA key pair (including the
host key and server key) of the server. The naming conventions for the keys are
switchname + host and switchname + server respectively.
After this command is entered, the system prompts you to input the number of
the key pair bits. Pay attention to the following:
■ The host key and the server key must have a difference of at least 128 bits in
length.
■ The minimum and maximum lengths for the host key and the server key are
512 bits and 2048 bits respectively.
Perform the following configuration in system view.
c
CAUTION:
■ Generating the RSA key pair of the server is the first step to perform after SSH
login.
■ This command needs to be performed only once; you need not re-perform it
after rebooting the switch.
■ If a key pair exists before the configuration, a prompt will appear asking if you
want to replace it.
■ When an SSH user logs in, the key generated by the server must be longer than
768 bits. By default, the key generated by the server is 1,024 bits.
Configuring the user authentication mode
Use this configuration task to specify the authentication mode for an SSH user.
You must specify an authentication mode for a new user; otherwise, the new user
will not be able to log in.
Note the following points:
1 The authentication mode configured for SSH users is used preferably. For example,
an SSH user is added whose service type is set to stelnet but configured with no
Tab le 715 Generate an RSA key pair
Operation Command
Generate an RSA key pair rsa local-key-pair create
Destroy an RSA key pair rsa local-key-pair destroy
Tab le 716 Configure the authentication mode for an SSH user
Operation Command Description
Enter system view system-view -
Configure an authentication
mode for SSH users
ssh user username
authentication-type {
password | rsa |
password-publickey | all }
By default, no login
authentication mode is
specified, that is, SSH users
are unable to log in.