tramp-default-method-alist

tramp-default-method-alist is a variable defined in `tramp.el'.
Its value is 


((nil "%" "smb")
 ("\\`\\(127\\.0\\.0\\.1\\|::1\\|Gandalf-Linux\\|localhost6?\\)\\'" "\\`root\\'" "su")
 (nil "\\`\\(anonymous\\|ftp\\)\\'" "ftp")
 ("\\`ftp\\." nil "ftp"))

Original value was


Documentation:
Default method to use for specific host/user pairs.
This is an alist of items (HOST USER METHOD). The first matching item
specifies the method to use for a file name which does not specify a
method. HOST and USER are regular expressions or nil, which is
interpreted as a regular expression which always matches. If no entry
matches, the variable `tramp-default-method' takes effect.

If the file name does not specify the user, lookup is done using the
empty string for the user name.

See `tramp-methods' for a list of possibilities for METHOD.

You can customize this variable.