5 ms·

Don't forget easy ssh host hopping. ssh -oProxyCommand="ssh host1 nc host2 22" host2

roadnottaken 16y ago
Interesting. Thanks for the tip! I'd never heard of ssh host hopping, but have been doing 2-3 sequential ssh logins for years. I always wondered if this was possible somehow! I found this nice tutorial that explains your tip in detail: http://sshmenu.sourceforge.net/articles/transparent-mulithop.html http://sshmenu.sourceforge.net/articles/transparent-mulithop... This made all the time I've spent on HN in the past week worthwhile! :)
- thristian 16y ago
  At $EMPLOYER, I have a script that takes a description of the network topology, converts it to a sequence of Host stanzas and writes them to ~/.ssh/config. The source file is simple enough that the sysad team can keep it up-to-date when they change the network configuration, and most people just have to run the 'update' script occasionally to have Super SSH Powers. It's quite popular.
  - roadnottaken 16y ago
    Don't suppose you'd be willing to post this uber-script somewhere?
    - thristian 16y ago
      Unfortunately it's not really self-contained enough to post; the most complicated thing in it is basically a copy/paste of the "Dijkstra's Algorithm" sample-code on Wikipedia, though.
rbarr 16y ago
I used nc to do just this for years until I switched companies and found that many of the hosts didn't have nc installed. To get around that I just added the following to my bashrc alias remote_host="ssh -t bastion ssh -t host1 ssh host2"
erikano 16y ago
Thanks for the tip, it inspired me to do the following: user@host3# ssh-keygen -t rsa -f ~/.ssh/id_rsa_hopping user@host3# echo command=\"nc host2 22\" `cat ~/.ssh/id_rsa_hopping.pub` | ssh user@host1 "cat >> ~/.ssh/authorized_keys" user@host3# scp ~/.ssh/id_rsa_hopping* user@host4:~/.ssh/ The point of all of this being that host4 should be able to do anything on host2, but only be able to use host1 as a hop: user@host4# ssh -oProxyCommand="ssh -i ~/.ssh/id_rsa_hopping host1" host2

Interesting. Thanks for the tip! I'd never heard of ssh host hopping, but have been doing 2-3 sequential ssh logins for years. I always wondered if this was possible somehow! I found this nice tutorial that explains your tip in detail: http://sshmenu.sourceforge.net/articles/transparent-mulithop.html http://sshmenu.sourceforge.net/articles/transparent-mulithop... This made all the time I've spent on HN in the past week worthwhile! :)

thristian 16y ago
At $EMPLOYER, I have a script that takes a description of the network topology, converts it to a sequence of Host stanzas and writes them to ~/.ssh/config. The source file is simple enough that the sysad team can keep it up-to-date when they change the network configuration, and most people just have to run the 'update' script occasionally to have Super SSH Powers. It's quite popular.
- roadnottaken 16y ago
  Don't suppose you'd be willing to post this uber-script somewhere?
  - thristian 16y ago
    Unfortunately it's not really self-contained enough to post; the most complicated thing in it is basically a copy/paste of the "Dijkstra's Algorithm" sample-code on Wikipedia, though.

rbarr 16y ago

I used nc to do just this for years until I switched companies and found that many of the hosts didn't have nc installed. To get around that I just added the following to my bashrc alias remote_host="ssh -t bastion ssh -t host1 ssh host2"

erikano 16y ago

Thanks for the tip, it inspired me to do the following: user@host3# ssh-keygen -t rsa -f ~/.ssh/id_rsa_hopping user@host3# echo command=\"nc host2 22\" `cat ~/.ssh/id_rsa_hopping.pub` | ssh user@host1 "cat >> ~/.ssh/authorized_keys" user@host3# scp ~/.ssh/id_rsa_hopping* user@host4:~/.ssh/ The point of all of this being that host4 should be able to do anything on host2, but only be able to use host1 as a hop: user@host4# ssh -oProxyCommand="ssh -i ~/.ssh/id_rsa_hopping host1" host2