Planning your IP address scheme
Designing the overall layout of your network is an incredibly important process that sets the stage for success or failure later on. This design must take into consideration the needs of the organization, the need for efficient methods of communication, and the segregation of network services to ensure that your servers can only communicate with the resources that they are supposed to. As a Linux administrator that manages a fleet of Ubuntu servers, it's not always the case that you'll even have a say in the network layout at all. It's quite common that you "inherit" a network designed by a previous administrator, or your job is siloed such that you only manage the servers and someone else is responsible for the network.
Since this is primarily a book that focuses on teaching you how to manage Ubuntu servers, we aren't going to cover all of the things that a network administrator would need to know, but there's...