This section has its focus on transitioning so-called unmanaged networks. Unmanaged networks are relatively small and simple networks that are not administered by competent technical personnel. Instead, such networks are setup and administered by their users. An example of an unmanaged network is the network in the home of a private person. Another example is the network of a small business. Such an unmanaged network typically consists of a single subnet connecting the equipment of the user. This subnet is connected via a small dedicated router to an Internet Service Provider. This router (also known as gateway) is normally not actively managed and it has been supplied and initially configured by the ISP. In some cases, however, the ISP may actively manage the gateway. In this setting, the home user has no control over the gateway. The user neither supplies nor configures nor manages the gateway that connects his network to the ISP. This restriction on the user may result in that the user adds an additional router between his home network and the gateway supplied by the ISP in order to gain control or add additional functionality. In the remainder, we will use the term gateway to refer to the router/gateway supplied by the ISP that provides the user with upstream connectivity.

Unmanaged networks were discussed by the last of the so-called deployment teams within the IETF v6ops working group. This deployment team has identified application requirements and relevant scenarios for transitioning unmanaged networks in “Unmanaged Networks Transition Scope”. Their work meanwhile reached information standard status and was published as RFC 3904 [RFC3904]. This is a short summary:

The main application requirements with regards to introducing IPv6 in an unmanaged network can be summarized by:

1. Applications running fine over IPv4 should continue to run fine after IPv6 is introduced in the network.
2. New applications that are hard to realize over IPv4 should be able to benefit from the introduction of IPv6 in the network.
3. Deploying new IPv6 applications should be simple and not create problems.

The unmanaged network topology includes 3 parts: the ISP, the gateway and user equipment. Each of these can either support IPv4, both IPv4 and IPv6 or can support IPv6 only. This gives 27 (3*3*3) combinations of IPv6 support in unmanaged networks. The IETF deployment team selected 4 out of these 27 scenarios for further consideration:

A. Gateway supports IPv4 only.
B. ISP and gateway support IPv4 and IPv6, i.e. they are dual-stack.
C. Gateway supports IPv6, but the ISP supports only IPv4.
D. ISP supports IPv6 only.

We refer to the draft for a more elaborate description of these scenarios.