SSH hacks – a little sanity for remote workers • Hacker News Board

SSH hacks – a little sanity for remote workers

#1

Post by mxfurman » Wed, Apr 29, 2020, 11:20 PM UTC

SSH hacks – a little sanity for remote workers
smallstep.com

Re: SSH hacks – a little sanity for remote workers

#2

Post by tomc1985 » Thu, Apr 30, 2020, 12:12 AM UTC

I miss having a job that required SSH'ing into a server to get work done. Nowadays everything is abstracted, push your code to the magic cloud and pull in 1000x other stupid little APIs. It's so boring...

Re: SSH hacks – a little sanity for remote workers

#3

Post by rubatuga » Thu, Apr 30, 2020, 12:16 AM UTC

You need to press Enter before using the SSH ~ escape key.

Re: SSH hacks – a little sanity for remote workers

#4

Post by segfaultbuserr » Thu, Apr 30, 2020, 12:21 AM UTC

> What are your favorite SSH tips & tricks?

    $ ssh -J user1@host1 user_final@host_final

or

    $ ssh -J user1@host1,user2@host2 user_final@host_final

Not many people know it, you don't need to launch a SSH within a SSH session - SSH has built-in support of using one SSH server as a proxy to another SSH server. Useful for hacking servers accessing servers behind a firewall, or using your own server as a proxy to bypass a bottleneck in the network.

Re: SSH hacks – a little sanity for remote workers

#5

Post by downerending » Thu, Apr 30, 2020, 12:22 AM UTC

rubatuga wrote: post #3

You need to press Enter before using the SSH ~ escape key.

Yup. I have no idea why they call it an escape character. It's an escape sequence, always of length two.

Re: SSH hacks – a little sanity for remote workers

#6

Post by mvanbaak » Thu, Apr 30, 2020, 12:27 AM UTC

tomc1985 wrote: post #2

I miss having a job that required SSH'ing into a server to get work done. Nowadays everything is abstracted, push your code to the magic cloud and pull in 1000x other stupid little APIs. It's so boring...

So, go make one of those APIs

Re: SSH hacks – a little sanity for remote workers

#7

Post by tashian » Thu, Apr 30, 2020, 12:30 AM UTC

downerending wrote: post #5

rubatuga wrote: post #3

You need to press Enter before using the SSH ~ escape key.

Yup. I have no idea why they call it an escape character . It's an escape sequence , always of length two.

And on an international keyboard it’s ~~, because ~ defaults to being a character modifier. If you nest SSH sessions, then you add more ~s. So in your fifth nested SSH session on an international keyboard the escape sequence would be \n~~~~~~~~~~.

Re: SSH hacks – a little sanity for remote workers

#8

Post by nprescott » Thu, Apr 30, 2020, 12:38 AM UTC

segfaultbuserr wrote: post #4

> What are your favorite SSH tips & tricks? $ ssh -J user1@host1 user_final@host_final or $ ssh -J user1@host1,user2@host2 user_final@host_final Not many people know it, you don't need to launch a SSH within a SSH session - SSH has built-in support of using one SSH server as a proxy to another SSH server. Useful for hacking servers accessing servers behind a firewall, or using your own server as a proxy to bypass a b…

This is a good one. I've used this in the past in order to get onto IPv6-only networks as well. In my case I don't have IPv6 enabled on my home internet (thanks Verizon!) and I had a tiny virtual machine with Vultr, which at their lowest price point aren't offering IPv4 address space any more. Using a jump through another machine with both 4 and 6 address space saved me from having to cough up more money solely for a IPv4 address.

Re: SSH hacks – a little sanity for remote workers

#9

Post by _wldu » Thu, Apr 30, 2020, 12:48 AM UTC

nprescott wrote: post #8

segfaultbuserr wrote: post #4

> What are your favorite SSH tips & tricks? $ ssh -J user1@host1 user_final@host_final or $ ssh -J user1@host1,user2@host2 user_final@host_final Not many people know it, you don't need to launch a SSH within a SSH session - SSH has built-in support of using one SSH server as a proxy to another SSH server. Useful for hacking servers accessing servers behind a firewall, or using your own server as a proxy to bypass a b…

This is a good one. I've used this in the past in order to get onto IPv6-only networks as well. In my case I don't have IPv6 enabled on my home internet (thanks Verizon!) and I had a tiny virtual machine with Vultr, which at their lowest price point aren't offering IPv4 address space any more. Using a jump through another machine with both 4 and 6 address space saved me from having to cough up more money solely for a…

Use teredo at home.

apt install miredo (on most debian based systems)

https://en.wikipedia.org/wiki/Teredo_tunneling

Re: SSH hacks – a little sanity for remote workers

#10

Post by davb » Thu, Apr 30, 2020, 12:49 AM UTC

segfaultbuserr wrote: post #4

> What are your favorite SSH tips & tricks? $ ssh -J user1@host1 user_final@host_final or $ ssh -J user1@host1,user2@host2 user_final@host_final Not many people know it, you don't need to launch a SSH within a SSH session - SSH has built-in support of using one SSH server as a proxy to another SSH server. Useful for hacking servers accessing servers behind a firewall, or using your own server as a proxy to bypass a b…

And in your ~/.ssh/config that's the ProxyJump directive. Adding a proper configuration for the bastion/jump host and for the target host means you can just to "ssh target".

In my case, I usually do "ssh target -t tmux -2 att" to attach to my tmux session, then when I detach it will close the SSH connection (and all of my tunnels).