IPAM, IP Address Management, used to be one of those things that network engineers didn’t think about too much. Most companies have implemented some form of automated IPAM. And even as vendors consolidated and disappeared, few enterprises put much thought into the need for an active IPAM strategy. But the need is now growing, thanks to several emerging trends.
First, networks continue to rapidly grow in size and complexity. And the growth isn’t coming in traditional terms of users and sites, it’s growing with respect to the number of devices: no longer just computers, but also phones, building control systems, surveillance systems, door controls, sensors and heavy machinery. The transition from an Internet of computers to an Internet of people and things means an explosion of connected devices, each with its own unique IP address. The average user now requires IP addresses for his computer, phone, and perhaps one or more mobile devices. Meanwhile, M2M communications are rapidly reshaping communications architectures. One recent research participant told me 70% of the devices on his network have no users. Rather they are sensors, cameras, process control systems, HVAC systems, and even building-access devices.
Secondly, IPv6 is increasingly on the radar of IT managers thanks to the growing press coverage of IPv4 address depletion. While it’s true that the Internet Assigned Number Authority has allocated its last remaining address blocks, regional registries still have a two- to three-year supply by most estimates. This means that IT architects have some to get ready, but they still must plan for IPv6 in the not-so-distant future.
Adopting IPv6 drives the need for automated IPAM. Most network engineers learn early on that binary math is critical for segmenting 32-bit IP addresses, calculating appropriate subnet masks, and so on. Comparing IPv4 to IPv6 in terms of address space is difficult because the human mind cannot easily grasp the numbers defined in exponential terms. In IPv4, there are 32-bits for the IP address, creating a total addressable space of 4.3 billion. Now this may seem like a lot, but on a planet inhabited by over 6 billion people, it imposes certain limitations. The usable space is further reduced by artificial subdivisions, leading to the broad adoption of Network Address Translation to conserve IP addresses.
IPv6 changes all of this by allocating 128 bits for the address, allowing for 3 x 1038 total IP addresses. And this is where the human brain balks: 10 followed by 38 zeros is a number with few physical equivalents outside the domain of cosmology. To provide a concrete example consider that with IPv6, each human on the planet could have an entire Internet’s worth of IP addresses. Although IPv6 includes some features that make address management simpler, the fact remains that it vastly increases the volume of addresses needing management.
To achieve a high level of availability and resilience to network outages, companies should consider building network services in an architecture that combines in-house and managed services. A hybrid architecture like this will combine on-premise specialized appliances with off-site managed appliances. This approach allows for separation of the management of internally facing resources (e.g. back-end servers) from externally facing resources (e.g. public-facing servers). It also ensures redundancy so that a company can maintain public presence through the external managed service, even if there are network outages or data center outages affecting the internal appliances.
While a combination of in-house appliances and externally hosted services is a pre-requisite for reliable network services, it is not sufficient.To achieve higher availability and stability, companies need to remove the most common source of problems: manual changes to network services. Inconsistent configuration of network services is commonly identified as a cause for network instability. By automating the configuration of network services, companies can ensure greater consistency of configuration, faster and more predictable upgrades, more reliable maintenance and change management.
Bottom line: revisit current IP Address Management solutions to ensure they are able to cope with rapid address growth now, and with IPv6 requirements in the future.
