There are three main ways that IPv6 has increased the need for service providers to adopt an IPAM solution:
Address Format and Size – IPv6 offers four times more address space than IPv4, which allows for just over 4 billion addresses. An IPv6 uses a 128-bit address, whereas IPv4 follows a 32-bit address scheme. The added complexity of IPv6 means that while an administrator may have once been able to remember an IPv4 address, some kind of IPAM tool is needed to keep track of IPv6 resources.
Compatibility – These two protocols will coexist for some time and providers need a solution that can organize address space when implementing these protocols side-by-side (in dual-stack mode). An IPAM solution allows you to catalog your IPv4 network resources, as well as IPv6 address space.
Routing Strategy – While previously it may have been possible to manage IPv4 address space using spreadsheets or manual systems, IPv6 is so large and complex that this is unworkable. You can allocate and track much larger blocks of addresses in IPv6 than you ever could in IPv4. Transitioning to IPv6, therefore, gives you the opportunity to redesign your entire networking infrastructure. Use IPAM to monitor your IPv6 deployment and re-adjust your strategy as required.