3com 5500-SI Manual De Usuario

SSH Terminal Services 201

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The client authenticates information from the user at the server till the 
authentication succeeds or the connection is turned off due to authentication 
timeout.

1 Password authentication works as follows: 

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The client sends its username and password to the server. 

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The server compares the username and password received with those configured 
locally. The user is allowed to log on to the Switch if the usernames and passwords 
match exactly. 

2 RSA authentication works in this way: 

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Configure the RSA public key of the client user at the server. 

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The client sends the member modules of its RSA public key to the server. 

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The server checks the validity of the member module. If it is valid, the server 
generates a random number, which is sent to the client after being encrypted with 
RSA public key of the client. 

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Both ends calculate authentication data based on the random number and session 
ID. 

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The client sends the authentication data calculated back to the server. 

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The server compares it with its authentication data obtained locally. If they match 
exactly, the user is allowed to access the switch. 

3 Session request stage. The client sends session request messages to the server which 

processes the request messages. 

4 Interactive session stage. Both ends exchange data till the session ends. 

Table 179 describes SSH server configuration tasks. 

Table 179   Configure SSH 2.0 server 

1

Configure supported 
protocols 

protocol inbound

Refer to “Configuring 
supported protocols”

2

Generate a local RSA key pair  rsa local-key-pair create Refer to “Generating or 

destroying RSA key pairs”

Destroy the local RSA key pair  rsa local-key-pair 

3

Configure authentication 
mode for SSH users

ssh user username 
authentication-type

Refer to “Configuring 
authentication type“

4

Set SSH authentication 
timeout time 

ssh server timeout

Refer to “Configuring 
server SSH attributes“

Set SSH authentication retry 
number

ssh server 
authentication-retries

5

Allocate public keys for SSH 
users 

ssh user username assign 
rsa-key keyname

Refer to “Configuring 
client public keys“