Connection / SSH1 / Advanced

This category only appears if VanDyke Software's SecureCRT® 5.0 (or newer) is also installed.

The SSH1/Advanced category of the Session Options dialog allows you to configure your SSH1
The first version of the SSH protocol which provides a way to encrypt network traffic between a client and a server. connection. The SSH1/Advanced category only appears when you have selected `SSH1` as your Protocol.

Cipher

The encryption
The process of converting a data transmission into a secret format that cannot easily be read by unauthorized individuals. See also: decryption. algorithm to use for data privacy. The default cipher is 3DES. DES, RC4, and Blowfish ciphers are also available for use with the SSH1 protocol. You may also set the cipher to `None`, which will effectively render your connection nonsecure. No encryption will occur if the cipher is set to `None`, and all data will be transmitted in plain text.

WARNING: Setting cipher to `None` causes the data channel to be left unencrypted and offers no security.

Cipher Speed Information -- The DES and 3DES ciphers are very CPU intensive (slow). The RC4 and Blowfish ciphers are considerably less CPU intensive (faster).

MAC (Message Authentication Code) (SSH2 Only)

The SSH2 protocol provides increased security over SSH1 by means of a MAC (Message Authentication Codes) which ensures data integrity. Although specifying a MAC is optional, it is highly recommended that a MAC be specified in order to ensure data integrity.

WARNING: Data integrity cannot be ensured if MAC is set to None.

SecureCRT will attempt to connect using the first selected MAC in the MAC list and then, if not successful, work down the list trying each selected MAC. To reorder the list, select the MAC that you want to reposition and use the buttons to the right of the list to move the MAC up or down.

Options group

Compression

Enable this option to have SecureCRT use compression when transferring data.

Level

This option controls the level of compression. The compression level ranges from 0 (minimal compression) to 9 (maximum compression). A higher level means better compression but slower performance. The default value is 5.

Enable OpenSSH agent forwarding

Check this option to use the agent to connect to a remote machine through another remote machine.

Force session channel to close on disconnect

When this option is checked and a session is disconnected by the user, SecureCRT will force the connection to close immediately without waiting for a response from the remote system.