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Protocol property

Determines protocol to use for connection.


  • Basic
object.Protocol [= value]
The Protocol(object) syntax has these parts:
objectAn expression evaluating to an object of type wodTelnetDLX


Protocol property is almost always set before new connection is made with remote server. Supported values are: Raw, Telnet, SSH1, SSH2, SSHAuto, SSL and SSLTelnet.

For Telnet protocol (Telnet and SSLTelnet), wodTelnetDLX expects to connect only to telnet based servers. Although it may seem to you that it's same as Raw type, Telnet provides a bit more than that. Under the hood, Telnet protocol specification describes specific 'codes' that are sent at the beginning of connection, and any time during connection, that are not visible to end user. wodTelnetDLX intercepts these codes, and sends answers back to remote server, providing you only plain connection. When SSLTelnet is used and remote server does not support SSL, wodTelnetDLX will close the connection thus providing you only secured connection - when possible.

Raw protocol is plaintext protocol (if it can be called protocol at all). It's purpose is to allow wodTelnetDLX to connect to any server which may be internally unsupported, allowing you to send/receive arbitrary data/commands, depending on remote server type. For instance, if needed, you can connect to remote server on port 25 and send SMTP commands, and even send email to someone. Since protocols like SMTP don't have any special codes, none of them need to be interpreted, so you will receive exactly what remote server sent you.

Very similar is SSL protocol also. Internally, wodTelnetDLX will encrypt/decrypt data exchanged with the server, but result you see will be in plaintext. Typical use for SSL protocol would be to connect to secured web servers.

SSH1 protocol is 'old-style' SSH protocol, which is popular among UNIX servers today. Almost all servers that support Telnet, support also SSH1 protocol. It's fully encrypted, and it's known to be secure - if DES algorithm is not used for encryption.

SSH2 protocol is somehow newer than SSH1 and uses more sophisticated protocol description. It supports far more encryption algorithms, and most of them are used with larger key values than in SSH1. Although name is similar, protocols are quite different and are not backward compatible.

SSHAuto protocol is a 'general SSH' protocol. If you set Protocol property to SSHAuto, then wodTelnetDLX will try to negotiate which SSH version will be used with remote server. Some servers support both SSH1 and SSH2, in which cases SSH2 will be selected. However, if server is SSH1 only, wodTelnetDLX will automatically fallback to SSH1 and use it.

You can check Protocol property later during connection to obtain selected protocol type value. Although you may have set it to SSHAuto (for example), wodTelnetDLX may change this value internally to SSH1 or SSH2 depending which SSH version it negotiated with remote server.

Please keep in mind that before new connection is established (with some other server) you should set this property back to SSHAuto. Changing Protocol property may also affect Port property.

When you set Protocol to Telnet or SSLTelnet, wodTelnetDLX will automatically set Port property to 23. If any SSH version is set, wodTelnetDLX will change Port property to 22. Since version, you can change Protocol property even after you connect to the server. You can do this only if you initially connected using Raw protocol, and want to upgrade your connection to SSL, all other combinations (at this moment) will result in an error.