3com 8807 User Guide

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The server initiates a procedure to authenticate the user. If the server is 
configured not to authenticate the user, the process proceeds to session 
request phase directly.

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The client employs an authentication mode to authenticate the server till the 
authentication succeeds or the server tears down the connection because of 
timeout.

n 

1 Password authentication procedure:

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The client sends the username and password to the server;

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The server compares the username and password sent from the client with the 
local configuration. If it finds an exact match, the authentication succeeds.

2 RSA authentication procedure:

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The server configures an RSA public key for the client;

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The client sends its RSA public key member module to the server;

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The server performs validity authentication on the member module. If the 
authentication succeeds, the server generates a random number, encrypts it 
using the RSA public key from the client, and sends the encrypted information 
back to the client;

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Both the server and the client uses the random number and the session ID with 
the length of 16 characters as parameters to calculate the authentication data;

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The client sends the authentication data it generates to the server;

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The server compares the authentication data from the client with that locally 
calculated. If they match, the authentication succeeds.

3 Session request: If the authentication succeeds, the client sends a session request 

to the server. When the server has successfully processed the request, SSH enters 
the interactive session phase.

4 Interactive session: The client and the server exchange data till the session is over.

The following table describes the SSH server configuration tasks.

Table 713   SSH2.0 configuration tasks

Enter system view 

system-view 

- 

Enter user interface view of 
VTY type 

user-interface vty X X 

- 

Set the protocol supported by 
current user interface 

protocol inbound { all | ssh | 
telnet } 

Optional 

Return to system view 

quit 

- 

Generate a local RSA key pair  rsa local-key-pair create 

Required 

Destroy a local RSA key pair 

rsa local-key-pair destroy 

Optional 

Configure the SSH user 
authentication mode 

ssh user username [ 
authentication-type { 
password | rsa | 
password-publickey | all } ] 

Required

By default, users are unable to 
log in.