TecMint published a tutorial about installing multiple CentOS or RHEL servers using FTP network sources.
How to Install Multiple CentOS/RHEL Servers Using FTP Network Sources
This tutorial will demonstrate how you can install RHEL/CentOS 8/7, using an FTP server (vsftpd) as Network Source. This allows you to install RHEL/CentOS Linux on multiple machines from a single source point.
How to Install Multiple CentOS/RHEL Servers Using FTP Network Sources