Linux Administration Cookbook

ProxyCommand

What we saw in our debug message was SSH translating the fairly simple ProxyJump entry into a ProxyCommand line.

ProxyCommand is the more traditional way of setting up this kind of forwarding, but not only is it syntactically more irritating, it's also messy.

Consider the following example:

Host * Port 22Host CentOS2-V4 Hostname 192.168.33.11 User vagrantHost CentOS3-V4 Hostname 192.168.33.12 User vagrant ProxyCommand ssh -v -W %h:%p CentOS2-V4

Looks more awkward, doesn't it? But it works in the same way.

This can be useful on older distributions, which maybe haven't received the ProxyJump feature yet.

If you ever forget the syntax for ProxyCommand and you have a box around that supports ProxyJump, remember that the ProxyCommand ...