tramp-connection-min-time-diff

tramp-connection-min-time-diff is a variable defined in `tramp.el'.
Its value is

5

Documentation:
Defines seconds between two consecutive connection attempts.
This is necessary as self defense mechanism, in order to avoid
yo-yo connection attempts when the remote host is unavailable.

A value of 0 or `nil' suppresses this check. This might be
necessary, when several out-of-order copy operations are
performed, or when several asynchronous processes will be started
in a short time frame. In those cases it is recommended to
let-bind this variable.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.4 of Emacs.