For years warnings have been issued regarding the looming exhaustion of IP addresses under the current IP addressing scheme. On January 31, 2011, the last two unreserved IANA /8 address blocks were allocated. The clock has finally run down for IPv4. The good news is, IPv4 address exhaustion only concerns the Internet and not the internal networks of most enterprises. Most home users are unlikely to need to take any action, as their ISPs will manage the issues.
Internet Protocol version 4 is the communications protocol that has formed the foundation for most current Internet communications, technically described in IETF publication RFC 791 . Existing enterprise networks often use private IPv4 addresses internally and rely on NAT at the perimeter to access the Internet by sharing a few public IPv4 addresses for all their internal users. There will be no immediate reason for this to change when IPv4 addresses are no longer available. Internal applications will be able to use IPv4 for some time, even after the Internet migrates completely to IPv6.
IPv6 is the next-generation of the IP protocol. Transitioning to IPv6 will soon become a requirement for enterprise networks. IPv6 enables significantly more IP addresses to accommodate the continuously growing number of worldwide Internet users, and provides additional security features for Internet traffic.
There have been many mitigation strategies attempted to avoid the exhaustion of IPv4 addresses, but have only extended the time availble to migrate to IPv6. The migration is inevitable, and the mitigations have had an undesired effect. In a survey recently conducted by IPswitch, 88% of business networks appear to be unprepared for a change to IPv6. 66.1% say their networks are less than 20% ready, despite the fact that the last blocks of IPv4 addresses have already been allocated.
- 0-20% ready – 66.1%
- 20-40% ready – 9.6%
- 40-60% ready – 6.5%
- 60-80% ready – 5.8%
- 80-100% ready – 12.0%
Adoption of IPv6 does pose migration, compatibility and management challenges for IPv4-based networks. IPswitch’s poll shows the need for companies to develop transitional strategies in order to increase IPv6 readiness and prevent any future disruption to mission-critical systems. Enterprises must understand the impact this migration will have on their services. They must assess their own situations and requirements as early as possible. This includes network, security and business applications.
Some strategies to consider:
|IPv6 is strategic in order to achieve business continuity:||Short-term migration plan should be prepared and executed, piloting in 2011 and in production in 2012.|
|IPv6 has its own value outside of IPv4-address exhaustion:||Mid-term migration plan can be prepared in 2011, with pilot in 2012 and production in 2012 or later.|
|IPv6 has no relevance to the business, shared IPv4 addresses do not break any apps:||Stay with IPv4 infrastructure and revisit the problem at the end of 2012.|
It is expected that for most enterprises, adding IPv6 connectivity to the Internet presence will be the highest priority, as they must offer services and content to IPv6 customers. Providing IPv6 access to all internal users and applications may be the next step if the enterprise is to move to cloud computing or web-based services. The last step will probably be adding IPv6 in the intranet and to data center applications. This will take longer as it will have a clear impact on business applications.
The time to start this planning has come and gone, so if your business hasn’t already started planning for IPv6, you are now behind the sweeping second hand. Several design guides and references that can help clarify the business and technical challenges in more detail are available. This is a short list of recommendations to start with:
- Deploying IPv6 in campus networks
- Deploying IPv6 in branch networks
- Cisco Podcast: IPv6 strategies
- Video: Google’s IPv6 Deployment Strategy
- Planning and Accomplishing IPv6 Integration: Lessons Learned from a Global Construction and Project Management Company
- U.S. Office of Management and Budget memorandum for CIOs “Transition to IPv6“
- Microsoft Active Directory and NAT
- What Companies Should Do About IPv6