Use of "Private Networking" with Contabo?

In the setup guide, Contabo is listed as a good, economical option for hosting a RocketPool node.

There’s a $2.99 add on for “Private Networking”:

I’m wondering, is this necessary? Is this just putting the instance behind a NAT or something? I am a real n00b when it comes to networking, so I’m not sure if this is a good or bad thing to use with RocketPool.