mosh

Mosh, short for Mobile Shell, is an open-source remote terminal application designed to provide roaming and resilient access to a shell on a remote computer. It is built to complement SSH by maintaining a persistent session even as the client moves between networks or experiences temporary connectivity losses.

How it works: A mosh client on the local machine connects to a mosh server running on the remote host. SSH is used for initial authentication and session setup, after which mosh uses its own stateful protocol to transmit keystrokes and terminal updates. This protocol typically operates over UDP and is designed to tolerate latency, packet loss, and IP address changes, allowing the user to roam across networks without reestablishing a new session. Local echo and predictive input handling help provide a responsive experience even when the connection is unstable.

Features and scope: Mosh supports interactive shells, including common terminal programs and editors, with automatic resynchronization when the network returns. It preserves the user’s terminal size and cursor position and can maintain a session across IP changes, sleep, or network interruptions. It is not a full replacement for SSH; certain SSH features such as port forwarding or X11 forwarding are not part of mosh’s protocol and may require alternative configurations if needed.

Availability: Mosh is available on many Unix-like systems, including Linux and macOS, with ports and equivalents for BSD systems and Windows (via environments such as Windows Subsystem for Linux or Cygwin). The remote host must have the mosh-server component installed, and the local machine must have the mosh client.