Related: A two-server three-jail network setup (firewall, vlan, tunnels)

https://blog.uidrafter.com/freebsd-jails-network-setup

       +-----------------+           +-----------------+         
       |                 |           |                 |         
  ----->  Reverse Proxy  |           |  Reverse Proxy  <-----
       |                 |           |                 |         
       +-----------------+           +-----------------+         
                |                             |                  
                |                             |                  
       +--------v--------+           +--------v--------+         
       |                 |           |                 |         
       |   App Server    \           /   App Server    |         
       |                 | \       / |                 |         
       +-----------------+   \   /   +-----------------+         
                |              X              |                  
                |             / \             |                  
       +--------v--------+  /     \  +--------v--------+         
       |                 |/         \|                 |         
       |     Database    <----------->     Database    |         
       |                 |           |                 |         
       +-----------------+           +-----------------+