IP Address Management (IPAM)

Organization of IP addresses, subnets and ranges

IPAM

Subnets are IP address areas that contain IP addresses. Subnets are normally specified based on the relevant subnet mask, which is a technically configured value on a network device that identifies the subnet. A subnet can then be divided into further areas, for example into sections for a specific customer or application scenarios within a subnet.

Example

Subnet: A subnet can look as follows:

Network-ID from/to Applied to
172.22.0.0/16 172.22.0.1 - 172.22.255.255 Location: Gersthofen, internal LAN

Range: Although the technical subnet is predetermined, a subnet can then also be subdivided into further sections. 
Possible examples for this scenario might be: Individual sections for firewall rules, device types and application areas

Network-ID from/to Applied to
172.22.0.0/24 172.22.0.1 - 172.22.0.254 Routers/Switches
172.22.1.0/24 172.22.1.1 – 172.22.1.254  Servers
172.22.2.0/24 172.22.2.1 – 172.22.2.254 Printers

IP Address: Once a range has been selected, its IP addresses will be listed. This will identify which IP addresses have been issued and which are still available, where necessary with their hostname.

172.22.0.1 active ROUTER-01
172.22.0.2 active ROUTER-02
172.22.0.3 active SWITCH-01

It is also important to realize that not all subnets have to be – or indeed can be divided into further sections For example, you might have a transfer network which only consists of two possible addresses. For this reason, the setup described above only serves as an aide to understanding ERAMON’s IPAM.