Digi TransPort WR11 User Manual page 545

Configuring Secure Shell (SSH) server and client
Enable support for SSH v1.5
When enabled, the server negotiates SSH V1.5. The router must also have a SSH V1 key
present and the filename entered into the SSG configuration.
Server key size
This option applies to V1 SSH. During initialization of an SSH session, the server sends its host
key and a server key (which should be of a different size to the host key). The router generates
this key automatically but the length of the server key is determined by this parameter. If
when this value is set it is too similar to the length of the host key, the router will automatically
adjust the selected value so that the key sizes are significantly different.
Enable support for SSH v2.0
When enabled, the server negotiates 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 enabled, this setting causes
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 using the current ones to
encrypt a specified amount of data. The radio buttons enable or disable this feature. If enabled,
enter the amount of data into the text box and select the applicable units (Kbytes, Mbytes,
Gbytes) from the drop-down list.
Encryption Preferences
The following configuration options allocate preferences to the encryption method to encrypt
data on the link. A lower value indicates greater preference. A value of 0 disables the option.
3DES
The preference level for the Triple-DES algorithm.
AES (128 bits)
The preference level for the 128-bit AES algorithm.
AES (192 bits)
The preference level for the AES algorithm using 192 bits.
AES (256 bits)
The preference level for the AES algorithm using 256 bits.
Digi TransPort® Routers User Guide
Configure SSH servers
545