Emacs Tramp ssh double hop

Question

Could somebody please help me setup Emacs Tramp to do a double hop? I want to work on machine2.abc.def.edu to which I can connect only through machine1.abc.def.edu. My usern

Answer 1

Set up an ssh tunnel from machine1 to machine2 (assuming that sshd runs on port 22 on machine2):

machine1.abc.def.edu> ssh -f -N -L 2222:localhost:22 machine2.abc.def.edu

Then either connect to machine2 from Emacs like this:

/ssh:machine1.abc.def.edu#2222

or add the following line to your .emacs:

(add-to-list 'tramp-default-proxies-alist
             '("\\`machine2\\.abc\\.def\\.edu\\'" nil
               "/tunnel:machine1.abc.def.edu#2222:"))