IPAM Address Management

by Leo Vegoda

“They always say time changes things, but you actually have to change them yourself,” according to Andy Warhol.

Manual tracking of IP address allocations has a long history. Many organizations used a spreadsheet to manage IP addresses. Having already paid for office productivity software why not use it as much as possible?

Gone are the days where IP address tracking was as simple as making sure sysadmins were told unique addresses.  IP address allocations are used to configure DNS, DHCP servers, geolocation information and more.  Automation is essential for networks of any size. The world is changing to require more data, which makes automated data maintenance more compelling.

Enter IPAM

The world today is completely different.  As interdependencies grow and data quality needs increase automation is required.  Automation not only reduces workload but enforces consistency as the data is consumed. 

IP Address Management, or IPAM, is the name given to tools that manage IP address allocations and interlinked information like DNS, DHCP scopes, and geolocation information.

IP Address Management (IPAM) automation tools all provide three core functions that are useful for all networks:

  • Network scanning, so you know what’s actually active on your network. Rogue device detection is important!
  • Network planning, so you know where addresses are used. Is that subnet in Datacenter 1 or Datacenter 2?
  • Integration with DHCP and DNS, so authorized clients get an appropriate IP address and associated DNS entries.

A recent addition is the need to manage geolocation data. In the 1990s all users could access services anywhere on the internet. Today some services are only available in particular areas. One example is live streams of sports events which are often licensed for specific territories.  IPv4.Global has written about this before and also described a free public tool for checking published geolocation information. The bottom line is that changes in the way GeoIP service providers get information will mean IPAM tools needing to support these capabilities. You can find a list of providers and their automation status here.

IPv6 Doubles the Work

Today networks need both IPv4 and IPv6 addresses. And most networks have more than one block of each. ARIN’s statistics show that most networks have 2.5 blocks, while the RIPE NCC’s show that organizations in Europe have more than 3.

Many organizations deploy hosts with both IPv4 and IPv6 addresses.  That often results in duplicating all the data entries.  IPAM software can allocate IPv6 addresses to existing IPv4 hosts automatically and will ensure that IPv4 and IPv6 addresses for a host are updated at the same time when changes are made.

Tracking Assignments Adds Complexity

RIRs use two words to describe IP address registrations. An allocation is a block of addresses assigned to a particular company. As the company divides that block into specific uses they call it an assignment.  Assignments might go to different internal teams, or different customers.

Some network operators encourage each other to register assignments. They use this information to inform automated policy implementation, like working out if they can provide a service.  RIRs also require assignment information when processing additional requests for space including IPv4 transfer requests.

Figure 1 shows how allocations, assignments, and the actual uses of IP addresses fit together.

Even small networks are likely to need four or five assignments for each allocation. It is not uncommon for an organization to update dozens of assignments and separate geofeed files on a regular basis. The answer is not to follow Andy Warhol’s advice and “change them yourself.”

IPv4.Global—A Trusted IPv4 Broker

Whether you’re building a brand new network and need addresses or simply want advice on IPAMs, contact us. We run the most transparent and trusted address brokerage. And we can connect you with engineers who can help you select the right tools for your organization – including IPAM tools that provide automatically generated GeoIP feeds as part of your provisioning process!