User`s guide

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Enable support for SSH v2.0
When checked, this checkbox allows the server to negotiate SSH V2. The router must also
have a SSH V2 key present and the filename entered into the SSG configuration.
Actively start key exchange
This option applies to V2 SSH. Some SSH clients wait for the server to initiate the key
exchange process when a new SSH session is started unless they have data to send to the
server, in which case they will initiate the key exchange themselves. When checked, this
checkbox will cause the router to automatically initiate a key exchange without waiting for
the client.
Rekey Never/After n units of data have been transferred
With SSH V2 it is possible to negotiate new encryption keys after the current ones have
been used to encrypt a specified amount of data. The radio buttons select whether this
feature should be used. If this feature is to be used the amount of data is entered into the
text box and the applicable units (Kbytes, Mbytes, Gbytes) selected from the drop-down list.
Encryption Preferences
The following four configuration options allocate preferences to the encryption method that
should be used to encrypt data on the link. A lower value indicates greater preference apart
from zero which disables the option.
3DES
The value in this text box is the preference level for the Triple-DES algorithm.
AES (128 bits)
The value in this text box is the preference level for the 128-bit AES algorithm.
AES (192 bits)
The value in this text box is the preference level for the AES algorithm using 192 bits.
AES (256 bits)
The value in this text box is the preference level for the AES algorithm using 256 bits.
Authentication Preferences
The following four configuration options allocate preferences to the authentication methods
that should be used. As above, a value of zero disables the particular authentication method
and lower values indicated greater preference than higher values. So, for example if MAC
SHA1-96 was the preferred method for authentication, this option would be given the value
1 and the other options given a value of 2 or greater. If all these parameters are set to the
same value, the router automatically uses them in the following order: SHA1, SHA1-96,
MD5, MD5-96.
MAC MD5
The value in this text box is the preference level for MAC MD5.
MAC MD5-96
The value in this text box is the preference level for MAC MD5-96.
MAC SHA1
The value in this text box is the preference level for MAC SHA1.
MAC SHA1-96
The value in this text box is the preference level for MAC SHA1-96.