Archive for the ‘IPv6 Benefits’ Category

IPv6 deployment will occur as a whisper, not as a bang

Monday, October 8th, 2007

IPv6 is the next generation Internet Protocol which is rapidly becoming this generation’s Internet Protocol.

IPv6 isn’t officially deployed in many places. However, unofficially it is deployed in most of today’s network environments.

At the command prompt of practically every current Linux, UNIX (including MacOS 10.4) and Windows (Vista) operating system, try the following in almost any office network and prepare to be surprised: ping “ff02::1” or “ping6 ff02::1.” Every IPv6-enabled network device in the office network will respond to this ping unless explicitly blocked by the network administrator (As defined by IETF RFC4291, ff02::1 is the IPv6 all nodes IPv6 address, which all nodes must respond to).

Although the network administrator may know nothing about IPv6, IPv6 is pervasive in most office networks.

Much of the controversy regarding IPv6 is a matter of policy. Meanwhile operating system designers have been silently enabling IPv6 by default. IPv6 is becoming an effective network protocol within Ethernet “broadcast” domains, even if network administrators haven’t configured its use across Ethernet domains and campus networks.

Because there is little fundamental difference between IPv4 and IPv6, the transition from IPv4 to IPv6 could occur as a whisper, not as a bang. Gradually network administrators will learn how to use IPv6 in their networks and will find transitioning to IPv6 less difficult or problematic as they originally feared.

IPv6 is not fully cooked. But neither is IPv4. Within 3-5 years it will be apparent that IPv4 can no longer support the needs of the global Internet community. It will also be apparent that a wholesale replacement to the Internet Protocol will take decades to design and implement. IPv6 will be the only viable protocol to support the ballooning global network infrastructure. IPv6 must happen.

The challenge of autoconfiguration vs. DHCPv6

Thursday, November 16th, 2006

Stateless Address Autoconfiguration is touted as a feature for IPv6. As the line goes, stateless address autoconfiguration makes it possible for small devices such as sensors to easily acquire their own IPv6 addresses.

Such a statement ignores the ground that DHCPv4 (which is typically only referred to as DHCP) has gained in the 12 years since IPv6 was first introduced and how pervasive and easy it has become. My $90 home wireless router can be both a DHCPv4 client and a DHCPv4 server. My home security camera has a DHCPv4 client. It is hard to think of many devices that would be too small or too simple that they couldn’t sport a DHCP client implementation.

So why is stateless address autoconfiguration so special? In my opinion, it isn’t. Even more so, there were few engineering types that I talked to at IETF in San Diego that thought stateless address autoconfiguration made more sense than DHCPv6.

One of the biggest problems with stateless autoconfiguration is that it cannot provide a client with DNS server addresses. This is a major drawback. This very limitation is one of the main contributors to the disappearance of the RARP protocol.

A possible easy fix for SAA not providing DNS server information existed with site local addressing. By default an operating system stack could look for a DNS server at specific site-local address if a DNS server address was not already defined. However, since site-local has been deprecated, this solution is no longer available.

One concern that pushes network administrators to select DHCPv6 over stateless address autoconfiguration is the perception that DHCPv6 provides more control than SAA does. There are some who think that this is primarily because administrators prefer DHCP because they are already familiar with it.

Time will tell if SAA becomes the mechanism of choice (or even a choice used anywhere) for acquiring IPv6 addresses. We will have to wait until functional DCHPv6 clients and servers exist before we can genuinely evaluate the merits of SAA and its place as a benefit of IPv6.