]> University of Southampton

Highfield Southampton SO17 1BJ Hampshire United Kingdom tjc@ecs.soton.ac.uk

Internet IPv6 Maintenance This text is intended to open discussion towards the adoption of support for tokenised IPv6 interface identifiers in IPv6 nodes. The primary target for such support is server platforms where addresses are usually manually configured, rather than using DHCPv6 or SLAAC. By using tokenised identifiers, hosts can still determine their network prefix by use of SLAAC, but more readily be automatically renumbered should their network prefix change.

The usual choices for IPv6 nodes to obtain addresses are Stateless Address Autoconfiguration (SLAAC) , DHCPv6 , or manual configuration. Client devices generally use SLAAC or DHCPv6. In the case of server systems, interface addresses are typically both static and manually configured. SLAAC is not used in case the interface hardware changes and the associated SLAAC generated address changes with it. DHCPv6 is often not used due to concerns of server stability should DHCPv6 fail. The disadvantage with static addresses is that they are likely to require manual editing should the network prefix in use change. If instead there were a method to only manually configure the static identifier part of the IPv6 address, then the address could be automatically updated when a new prefix was introduced, as described in for example. In such cases a DNS server might be configured with such a tokenised interface identifier of ::53, and SLAAC would use the token in constructing the interface address, using the advertised prefix.

The author is aware of support for tokenised IPv6 identifiers in Solaris, and of a proof of concept implementation for Linux. Under Solaris, tokenised identifiers can be configured directly with ifconfig, e.g. ifconfig qfe0 inet6 token ::53/64 or the configuration can be made persistent by adding a line to the appropriate /etc/hostname6.interface file. In the Linux proof of concept implementation , a command line can be used to configure the interface: ip6token eth0 ::53 The specifics of how such tokenised identifiers are configured are likely to be operating system dependent. The important point is that such identifier configuration should be supported.

This approach would address in part the problems discussed in in Sections 2.3 and 2.8, for the address configuration of server systems. While a broader solution for the management of static addresses is desirable, tokenised identifiers present a useful interim step, if vendors choose to support the concept.

It would be desirable if all potential IPv6 server platforms supported tokenised interface identifiers. There may also be benefits for other IPv6 nodes to do so. The author welcomes feedback on this draft, and any comments on platforms currently supporting such identifier configuration, or any reasons why wider implementation should not be considered.

There are no extra security consideration for this document.

There are no extra IANA consideration for this document.

The author thanks the 6NET project under which considerations of tokenised identifiers was originally made, and colleague (at the time) Mark Thompson for his proof of concept implementation of such identifiers on a Linux platform.

&rfc3315; &rfc4192; &rfc4862; &I-D.ietf-6renum-static-problem;