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Comment by foxpurple | Hacker News Reader

The title “Mosh: SSH for 2012” is amusing because now in 2021, ssh is still king.

I disagree. SSH is fine for short connections (like git push or running some Ansible playbook), but it's far too fragile for longer uses. For example, if you're running something like dd with no output, you end up in a situation where you're not sure if dd is still running or did your connection just break.

With mosh, I could start dd, close my laptop, move to a cafe, open up my laptop, and know for certain I'll re-establish the connection when I'm back online.

If you have long running operations you can use screen/tmux.

You can use screen/tmux, but they’re both more complicated and less good when it comes to this specific use-case.

Personally I use both - mosh (or et) for the seamless automatic-reconnect, and tmux as a console window-manager.

> You can use screen/tmux, but they’re both more complicated...

In what way are they more complicated? Granted screen is legacy, but tmux is just an executable on the server with sane defaults that Just Works OOTB.

> In what way are they more complicated?

When you change wifi networks you either have to remember to manually disconnect in advance, or wait for ssh to time-out the connection, then you have to create a new ssh connection, then you have to run an extra command to re-attach to the {screen/tmux} session you started earlier.

It’s not insurmountably difficult work - but for the specific use-case of roaming across wifi networks, “doing a small disconnect and reconnect dance” with tmux is way more complicated and annoying than “open your laptop and all your connections are still working” with mosh.

What? Instead of ./command you type screen ./command.

Will `screen ./command` automatically and seamlessly reconnect my ssh session when I roam between different wifi networks? Or do I need to reconnect to ssh for myself, and then run a second command to reattach to the screen session?

The second.

In general, I prefer SSH when using reliable, low-latency links, mainly because of the various forwarding capabilities (agent, X11, ports), and sometimes because I need my output to be sequential. But for any kind of situation where the link might be dodgy, mosh is king.

Indeed, a common paradigm is to use mosh to connect over the internet to some bastion host, and then use ssh for all subsequent connections over a highly reliable internal network.

SSH is great and full-featured, and mosh uses it for the initial connection, but try mosh if you haven't. I did years ago and never looked back.

It reconnects immediately over any connection and works so well you can miss 15% packet loss. SSH feels so brittle next to it.

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