Two years later, still sticking with IPv4

By Chuck Yoke
Network World, 05/13/02

A little more than two years ago, I wrote my first column for Network World. The topic was IPv6 and my opinion was that while IPv6 may have some use, I was going to stick with IPv4 "for now." Well, two years later, I'm still sticking with IPv4.

While IPv6 provides features that may be valuable to a carrier-class network provider, the ubiquitous IPv4 still provides me with all the network capabilities and features I need to design, implement and manage global corporate networks.

The one item that initially interested me about IPv6 - the extended address space - essentially has little or no value to me anymore. By using the private 10.0.0.0 address space and network address translation (NAT), I have more than enough IP addresses. And if I run out of addresses, I can always use NAT with 5.0.0.0, 7.0.0.0 or one of the other Internet Assigned Numbers Authority reserved addresses. While they are technically not designated for private address use, almost all ISPs have applied the appropriate filters in their infrastructures to ensure these addresses do not get propagated to the Internet. Even if I had a registered IPv6 (or even IPv4) address space, very few ISPs would let me use it to access the Internet natively. To reduce the load on their Border Gateway Protocol routing tables, most ISPs require I use addresses from their block of registered addresses.

As for security, even though IPv6 offers enhanced native security features such as authentication headers and encapsulating security payloads, I can use optional IP Security extensions to bring these features to my IPv4 infrastructure. With today's business emphasis on security and return on investment, few network security departments would be willing to throw out their trusted IPv4 investments and implement a new infrastructure. Their IPv4-based firewalls - combined with Triple-DES encryption, Remote Authentication Dial-In User Service and Challenge Handshake Authentication Protocol - have been designed and configured to provide the required level of network security at low cost. IPv6 brings nothing to the corporate security table that can't be done in a correctly configured IPv4 environment.

While IPv6 provides native quality of service via the flow label header field that can identify and route traffic by flows, IPv4-based options such as traffic shaping, Differentiated Services and Multi-protocol Label Switching meet the majority of corporate QoS needs.

A crucial consideration of any technology is support costs. I know of very few people who have the necessary training and experience to design a global IPv6 network. On the other hand, there are many workforce professionals trained and experienced in IPv4.

While IPv6 provides a very elegant technical solution, the tried-and-true IPv4 provides corporations with all the network functionality they need at a lower cost. And in the business world, that makes IPv4 "the winner and still champion."