IPv4 uses a 32-bit address format,  which provides approximately 4.3 billion unique IP addresses. IPv6 Dramatically Increases Address Space

IPv6 dramatically increases the amount of IP address space available from  the approximately 4.3 billion addresses in IPv4 to approximately 3.4 × 10IPv6 addresses are characterized by a network prefix that describes the  location of an IPv6-capable device in a network and an interface ID that  provides a unique identification number (ID) for the device. IPv6 Considerations Include Significant Planning Efforts and Immediate Actions to Ensure Security

Key planning considerations for federal agencies include recognizing that  an IPv6 transition is already under way because IPv6-capable software and  equipment exist in agency networks. Furthermore, specific security risks could result from not managing IPv6  software and equipment in federal agency networks. One key aspect to consider while  drafting the business case for IPv6 is to understand how many devices an  agency wants to connect to the Internet. Progress Has Been Made at Defense but Is Lacking at Other Federal Agencies

Recognizing the importance of planning, DOD has made progress in  developing a business case, policies, a timeline, and methods for  transitioning to IPv6, but similar efforts at the majority of the other CFO  agencies are lacking. Majority of Federal Agencies Have Not Initiated Transition Planning Efforts

Unlike DOD, the majority of other federal agencies reporting have not yet  initiated transition planning efforts for IPv6. Conclusions

The increase in IPv6 address space and the other new features of the  protocol are designed to promote flexibility, functionality, and security in  networks. Instruct federal agencies to begin addressing key IPv6 planning  considerations, including  developing inventories and assessing risks,  creating business cases for the IPv6 transition,  establishing policies and enforcement mechanisms,  identifying timelines and methods for transition, as appropriate. Objectives, Scope, and Methodology

The objectives of our review were to  describe the key characteristics of Internet Protocol version 6 (IPv6);  identify the key planning considerations for federal agencies in  transitioning to IPv6; and  determine the progress made by the Department of Defense (DOD) and  other major federal agencies to transition to IPv6.
Why GAO Did This Study

The Internet protocol (IP) provides the addressing mechanism that defines how and where information such as text, voice, and video move across interconnected networks. Internet protocol version 4 (IPv4), which is widely used today, may not be able to accommodate the increasing number of global users and devices that are connecting to the Internet. As a result, IP version 6 (IPv6) was developed to increase the amount of available IP address space. It is gaining momentum globally from regions with limited address space. GAO was asked to (1) describe the key characteristics of IPv6; (2) identify the key planning considerations for federal agencies in transitioning to IPv6; and (3) determine the progress made by the Department of Defense (DOD) and other major agencies to transition to IPv6.

What GAO Found

The key characteristics of IPv6 are designed to increase address space, promote flexibility and functionality, and enhance security. For example, by using 128-bit addresses rather than 32-bit addresses, IPv6 dramatically increases the available Internet address space from approximately 4.3 billion addresses in IPv4 to approximately 3.4 x 10^38 in IPv6. Key planning considerations for federal agencies include recognizing that the transition is already under way, because IPv6-capable software and equipment already exists in agency networks. Other important agency planning considerations include developing inventories and assessing risks; creating business cases that identify organizational needs and goals; establishing policies and enforcement mechanisms; determining costs; and identifying timelines and methods for transition. In addition, managing the security aspects of an IPv6 transition is another consideration since IPv6 can introduce additional security risks to agency information. For example, attackers of federal networks could abuse IPv6 features to allow unauthorized traffic or make agency computers directly accessible from the Internet. DOD has made progress in developing a business case, policies, timelines, and processes for transitioning to IPv6. Despite these efforts, challenges remain, including finalizing plans, enforcing policy, and monitoring for unauthorized IPv6 traffic. Unlike DOD, the majority of other major federal agencies reported not yet having initiated key planning efforts for IPv6. For example, 22 agencies lack business cases; 21 lack transition plans; 19 have not inventoried IPv6 software and equipment; and none had developed cost estimates.