Multiple hops are configured with the variable
tramp-default-proxies-alist (see Multi-hops). However,
sometimes it is desirable to reach a remote host immediately, without
configuration changes. This can be reached by an ad-hoc specification
of the proxies.
A proxy looks like a remote file name specification without the local file name part. It is prepended to the target remote file name, separated by ‘|’. As an example, a remote file on ‘you@remotehost’, passing the proxy ‘bird@bastion’, could be opened by
C-x C-f /ssh:bird@bastion|ssh:you@remotehost:/path
Multiple hops can be cascaded, separating all proxies by ‘|’.
The proxies can also contain the patterns
The ad-hoc definition is added on the fly to
tramp-default-proxies-alist. Therefore, during the lifetime of
the Emacs session it is not necessary to enter this ad-hoc
specification, again. The remote file name ‘/ssh:you@remotehost:/path’ would be sufficient from now on.
This customer option controls whether ad-hoc definitions are kept
tramp-default-proxies-alist. That means, those
definitions are available also for future Emacs sessions.