I record my reconnection and it works fine. But, is it possible to run reconnection from command line? For examle to have a shortcut that will automatically run jdownloader and change my IP or to make application that will change it.

Reconnection is controlled by jD itself. If that wouldn't be the case, you would disconnect jD while it's downloading.

Just enable the automatic reconnect feature.

[drbits]

remi is right.

If automatic reconnect is enabled, then reconnection occurs whenever it is necessary, including at the beginning or end of a JDownloader session.