Carving up and assigning private IP address (RFC 1918 addresses) space is big subject and can be daunting of you have a large enterprise today, especially with mergers. Even when you have a centralized IP address management system (IPAM), you will find undocumented address space being used and sometimes finding useable space is difficult. However we want to find large non-fragmented spaces so we can create a well-summarized network. Don’t laugh, we all like a challenge, right? In our case we found that the 10.0.0.0/11 space was available (I know, fiction, right?). So, we are going to carve up /13’s for our production and non-production and we will grab a /16’s for our shared service and a /16 for our simulated datacenter. What does that mean?
##Datacenter IP Addresses We also will carve out a /16 CIDR for our Datacenter. In the real world this will likely be a list of many summarized CIDRs, both rfc 1918(private address space) and public IP CIDRs (addresses typically assigned to your organization from the Internet Assigned Numbers Authority (IANA) )