Goals of Detecting Network Attachment in IPv6
RFC 4135
Document | Type |
RFC - Informational
(August 2005; No errata)
Was draft-ietf-dna-goals (dna WG)
|
|
---|---|---|---|
Authors | JinHyeock Choi , Greg Daley | ||
Last updated | 2015-10-14 | ||
Stream | Internet Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 4135 (Informational) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Margaret Cullen | ||
Send notices to | Pekka.Nikander@nomadiclab.com |
Network Working Group JH. Choi Request for Comments: 4135 Samsung AIT Category: Informational G. Daley CTIE Monash University August 2005 Goals of Detecting Network Attachment in IPv6 Status of This Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2005). Abstract When a host establishes a new link-layer connection, it may or may not have a valid IP configuration for Internet connectivity. The host may check for link change (i.e., determine whether a link change has occurred), and then, based on the result, it can automatically decide whether its IP configuration is still valid. During link identity detection, the host may also collect necessary information to initiate a new IP configuration if the IP subnet has changed. In this memo, this procedure is called Detecting Network Attachment (DNA). DNA schemes should be precise, sufficiently fast, secure, and of limited signaling. Table of Contents 1. Introduction ....................................................2 2. Problems in Detecting Network Attachment ........................3 2.1. Wireless Link Properties ...................................3 2.2. Link Identity Detection with a Single RA ...................3 2.3. Delays .....................................................4 3. Goals for Detecting Network Attachment ..........................5 3.1. Goals List .................................................6 4. Security Considerations .........................................6 5. Acknowledgements ................................................7 6. References ......................................................8 6.1. Normative References .......................................8 6.2. Informative References .....................................8 Choi & Daley Informational [Page 1] RFC 4135 DNA Goals August 2005 1. Introduction When a host has established a new link-layer connection, it can send and receive some IPv6 packets on the link, including those used for configuration. On the other hand, the host has Internet connectivity only when it is able to exchange packets with off-link destinations. When a link-layer connection is established or re-established, the host may not know whether its existing IP configuration is still valid for Internet connectivity. A subnet change might have occurred when the host changed its point of attachment. In practice, the host doesn't know which of its addresses are valid on the newly attached link. It also doesn't know whether its existing default router is on this link or whether its neighbor cache entries are valid. Correct configuration of each of these components is necessary in order to send packets on and off the link. To examine the status of the existing configuration, a host may check whether a 'link change' has occurred. In this document, the term 'link' is as defined in RFC 2461 [1]. The notion 'link' is not identical with the notion 'subnet', as defined in RFC 3753 [2]. For example, there may be more than one subnet on a link, and a host connected to a link may be part of one or more of the subnets on the link. Today, a link change necessitates an IP configuration change. Whenever a host detects that it has remained at the same link, it can usually assume its IP configuration is still valid. Otherwise, the existing one is no longer valid, and a new configuration must be acquired. Therefore, to examine the validity of an IP configuration, all that is required is that the host checks for link change. In the process of checking for link change, a host may collect some of the necessary information for a new IP configuration, such as on- link prefixes. So, when an IP subnet change has occurred, the host can immediately initiate the process of getting a new IP configuration. This may reduce handoff delay and minimize signaling. Rapid attachment detection is required for a device that changes subnet while having on-going sessions. This may be the case if a host is connected intermittently, is a mobile node, or has urgent data to transmit upon attachment to a link. Detecting Network Attachment (DNA) is the process by which a host collects the appropriate information and detects the identity of its currently attached link to ascertain the validity of its IP configuration. Choi & Daley Informational [Page 2]Show full document text