Accelerating OpenSSH connections with ControlMaster

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HowTos

OpenSSH 4.0 introduced an interesting new feature called ControlMaster that allows it to reuse an existing connection to a remote host when opening new connections to that host. This can significantly reduce the amount of time it takes to establish connections after the initial connection. Let's see how this can help you work faster, and how to start using ControlMaster right away.

The reduced connection times that the ControlMaster feature provides are particularly nice when you're using tools that open multiple SSH connections to do work on a remote server, such as:

*Using Emacs on the client with Transparent Remote (file) Access, *Multiple Protocol (TRAMP) to access files on a remote server via SSH
*Using the SSH Filesystem (SSHFS) feature of Filesystem in Userspace (FUSE)
*Accessing a remote Concurrent Versioning System (CVS) or Subversion repository via an SSH tunnel
*Remote filename completion in a shell such as bash or zsh, or in Emacs using TRAMP for that matter

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