What options exists under CentOS hosts to work with isolated networks?. For example, on BSD systems it is really trivial. In FreeBSD you can use setfib tools and on OpenBSD it is possible to use rdomain options. In 30 secs it is possible to work with isolated networks and assign process, ip address and routes (hidden from the main route table and ip addresses), etc.
But I can’t find a similar solution for CentOS environments. I have found two similar options:
a/ Network namespaces (but doesn’t provides a real network isolation)
b/ VRF (but it is supported only for kernels 4.8 and up)