I blew a few minds a week ago when I told my younger coworkers about man pages. I hit ‘em with the `man man` and one dude was like “whoa!”

HN as a tabloid ... After all enquiring minds want to know!

hahaha made me laugh, thanks :-D

If hung SSH connections are common it's likely due to CGNAT which use aggressively low TCP timeouts. e.g. I've found all UK mobile carriers set their TCP timeout as low as 5 minutes. The "default" is supposed to be 2 hours, you could literally sleep your computer, zero packets, and an SSH connection would continue to work an hour later, and generally speaking this is still true unless CGNAT is in the way.

If you are interested there are a few ways you can fix this:

Easiest is to use a VPN, because the VPN's exit node becomes the NAT they usually have normal TCP timeouts due to being less resource constrained. Another nice benefit of this method is you can move between physical networks and your connection doesn't die... If you use Tailscale then you already have this in a more direct way.

Another is to tune the tcp_keepalive kernel parameters. By default these are set up to send probes after 2 hours to see if the other side is still there. If you lower this to be less than the CGNAT timeout then the TCP probes will help prevent CGNAT from dropping the connection even while your SSH connection is technically idle. For Linux I pop these into /etc/sysctl.d/z.conf, I have no idea for Windows or Mac:

  net.ipv4.tcp_keepalive_time   = 240 
  net.ipv4.tcp_keepalive_intvl  = 60
  net.ipv4.tcp_keepalive_probes = 120

_time=240 will send a probe after 4 mins of idle connection instead of the default 2 hours, undercutting the CGNAT timeout. _intvl=60 and _probes=120 mean it will send 120 probes 60 seconds apart (2 hours worth) before considering the connection dead, the idea here is to have the best of both worlds, so that under a nice NAT it keeps the old behaviour and if I temporarily lose my network the SSH connection is still valid after 2 hours, but under CGNAT it will at least not drop the connection after 5 mins so long as I keep my computer on and don't lose the network.

There are also some SSH client keepalive settings but I'm less familiar with them.

Have been using that weekly since probably 20 years. Will change your life :)

My other favourite is I very often SSH with -v to figure out why the connection is hanging, you rapidly figure out if DNS is failing, the TCP connection doesn't open, it does open but no traffic flows at all or it opens and SSH negotiation starts but never finishes. You can learn a lot just from this about what is wrong.

You can even chain them if you have deep ssh connections (i.e. ssh from one instance to another). I think it would be ~~. to terminate the 2nd hop.

Edit: it's already explained in the OP

> It's much nicer than my current approach of having to close that terminal window.

You can also just kill the ssh process (say from another terminal). That way you get to keep your terminal window. And this works with everything "blocking" your terminal, not just ssh.

I use that every day but it's the only one I know by heart lol

I've been using ~. on hung ssh connections for a while.

"secret" not in the sense that it's hidden, but that most people won't know about it. Because approximately nobody actually reads man pages in their entirety, they just get in to find out how a specific flag works and then get out.

I typically just create a "new" connection in a separate tab when I want to add tunneling.

I put new in quotes because I use another little-known feature, "ControlMaster". Multiplexes multiple connections into one, it makes making " new" sessions instant (can also be configured to persist a bit after disconnecting). Also useful for tab-completing remote paths. It does not prompt for authentication again, though. And it's a bit annoying when the connection hands (can be solved with ssh -o close, IIRC).

Note that it only works after pressing enter, so the odds are slim. In practice, I don't think I ever hit it by accident.

SSH does it pretty well though. Never once have I done it by mistake.