ProxyJump and bastion hosts

We're going to take a look at one very new SSH option, a slightly older SSH option, and the concept of bastion hosts (or jump boxes) in this recipe.

We need three machines because we're going to use one machine as the "gateway" to another.

Getting ready

Set up your three VMs, preferably using the Vagrantfile at the top of this chapter.

Connect to each box, and then check that from centos1, you can ping centos2 and centos3:

[vagrant@centos1 ~]$ ping 192.168.33.11
PING 192.168.33.11 (192.168.33.11) 56(84) bytes of data.
64 bytes from 192.168.33.11: icmp_seq=1 ttl=64 time=2.54 ms
64 bytes from 192.168.33.11: icmp_seq=2 ttl=64 time=1.09 ms
64 bytes from 192.168.33.11: icmp_seq=3 ttl...