8-1 
8  SSH2.0 Configuration 
When configuring SSH2.0, go to these sections for information you are interested in: 
z  SSH2.0 Overview 
z  Configuring the Device as an SSH Server 
z  Configuring the Device as an SSH Client 
z  Displaying and Maintaining SSH 
z  SSH Server Configuration Examples 
z  SSH Client Configuration Examples 
SSH2.0 Overview 
Introduction to SSH2.0 
Secure Shell (SSH) offers an approach to securely logging into a remote device. By encryption and 
strong authentication, it protects devices against attacks such as IP spoofing and plain text password 
interception. 
The device can not only work as an SSH server to support connections with SSH clients, but also work 
as an SSH client to allow users to establish SSH connections with a remote device acting as the SSH 
server.  
 
 
Currently, when acting as an SSH server, the device supports two SSH versions: SSH2.0 and SSH1. 
When acting as an SSH client, the device supports SSH2.0 only. 
 
Operation of SSH 
The session establishment and interaction between an SSH client and the SSH server involves the 
following five stages: 
Table 8-1 Stages in session establishment and interaction between an SSH client and the server 
Stages  Description 
Version negotiation 
SSH1 and SSH2.0 are supported. The two parties negotiate a 
version to use. 
Key and algorithm negotiation 
SSH supports multiple algorithms. The two parties negotiate an 
algorithm for communication. 
Authentication 
The SSH server authenticates the client in response to the 
client’s authentication request.