Network Working Group Yuankui zhao Internet-Draft Shanghai Huawei Technology Intended status: Standards Track July 1, 2007 Expires: Jan 1, 2008 Default gateway consideration for netlmm draft-zhao-netlmm-ra-consideration-00 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on September 5, 2007. Copyright Notice Copyright (C) The Internet Trust (2007). Yuankui zhao Jan 1,2008 [Page 1] Internet-Draft Default gateway consideration for netlmm Jul 2007 Abstract RA sent to inform MN about the network prefix and gateway existed.But within a netlmm domain,MN should think that it's home network is kept unchanged when it is roaming and it's default gateway is unchanged is the best.But current the netlmm draft only can make the MN know the home network prefix.It can't give a convience way to make the gateway keep unchanged when the MN is roaming within a netlmm domain. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. The source address of RA . . . . . . . . . . . . . . . . . . . 5 3.1 The original of this link-local address. . . . . . . . . . . 5 3.2 Let the new access router know this address. . . . . . . . . 5 4. IPv4 considerations . . . . . . . . . . . . .. . . . . . . . 6 5. Security Considerations . . . . . . . . . . . . . . . . . . . 7 6. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 8 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 7.1. Normative References . . . . . . . . . . . . . . . . . . . 9 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11 Intellectual Property and Copyright Statements . . . . . . . . . . 12 Yuankui zhao Jan 1,2008 [Page 2] Internet-Draft Default gateway consideration for netlmm Jul 2007 1. Introduction In IPv6 scenario, the RA messages are sent to inform MN about the network prefix and related gateway.And after receiving a RA from a new address, MN would insert that into the default gateway list with the compound with that prefix it advisted. Within a netlmm domain,MN didn't know anything about the change of the network. Network side keep the MN believe it still always stay in it's home network. For achieving this goal, we should always sent the same home prefix to a MN within a netlmm domain. Meanwhile,we also need to keep the default gateway is the same to that MN during this progress. But current the netlmm draft only can sent to MN the same home network prefix.It can't give a convience way to make the gateway keep unchanged when the MN is roaming within a netlmm domain. For this reason,in this draft we provide a method to make MN didn't feel the change of default gateway within a netlmm domain. 1.1. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 RFC 2119 [STANDARDS]. Yuankui zhao Jan 1,2008 [Page 3] Internet-Draft Default gateway consideration for netlmm Jul 2007 2. Overview The source address of RA is the link-local address of the AR.When a MN enter into a network,after it receive the RA messages,it will extract the source address of RA and appended with the prefix in this message to construct an address. When a Neighbour discovery progress aimed to this address is proceeded and that address is certified to be valid,the address will become the default address of this MN.Thus if a RA come from the new address,then that new address will be inserted into the default gateway lists of the MN. And when the previous one can't be used again, MN will use a implement method to choose a candidate address to become the new default gateway. Of course, if there is no one is existed,the MN will start a new progress to discover the default gateway. For this reason,within a netlmm domain,we should keep the source address of the RA sent to MN didn't be changed after that MN has entered into the network. As to the detail methods,we think the HA's link-local address is the best. Of course,the original link-local address should be kept as the source address of RA next to send to the MN.For keep to use that link-local address,a context mechnism is needed,otherwise we can use the AAA to forward it. Yuankui zhao Jan 1,2008 [Page 4] Internet-Draft Default gateway consideration for netlmm Jul 2007 3. The source address of RA In IPv6 context,the source address of RA is a link-local address of AR.It's used to formed the candidated dateway by MN.After construct a global address,the default gateway selection algorithm is a implementation method. Within a netlmm domain,we should keep the address unchanged in order to let MN believe it still stay in the original network.And that is it's home network. Otherwise,will accuse the MN initial the new router discovery progress to choose a new AR as the default gateway. For keep this address the same as that is originally sent to MN. Following rule is taken into account: 3.1 The original of this link-local address This link-local address can be the link-local address of the MN's HA .Or,it can be the same as the link-local address of that initial access router provided to MN when it enter into network initiallly. 3.2 Let the new access router know this address This link-local address can be learnt by new access router via the context transfer mechniasm or to download fram AAA. To the previous method,that is very easy to understand,but difficult to get the consistent agree to deploy the context tranfer mechnism. As to the last one,That can be deploied when the context transfer mechnism is unaviliable. Yuankui zhao Jan 1,2008 [Page 5] Internet-Draft Default gateway consideration for netlmm Jul 2007 4. IPv4 considerations TBD. Yuankui zhao Jan 1,2008 [Page 6] Internet-Draft Default gateway consideration for netlmm Jul 2007 5. Security Considerations All of the progresses and messages used at here is what currently supported by MN.They all can use the current relevent security method to guarantee their security.We didn't introduce and discuss any new security mechnism to this draft. Yuankui zhao Jan 1,2008 [Page 7] Internet-Draft Default gateway consideration for netlmm Jul 2007 6. Conclusions The material used to let MN construct default gateway address and the default gateway address need to be kept unchanged within a netlmm domain. Some identifier of the default gateway also need to be considered to kept unchanged if necessary within a netlmm domain. All of above what we have discussed is aimed to a MN within a netlmm domain.Meanwhile the above is applied to P2P link mode.To shared link mode, that will need to be appended in the future. Yuankui zhao Jan 1,2008 [Page 8] Internet-Draft Default gateway consideration for netlmm Jul 2007 7. References 7.1. Normative References [STANDARDS] "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, March 1997, . Yuankui zhao Jan 1,2008 [Page 9] Internet-Draft Default gateway consideration for netlmm Jul 2007 8. IANA Considerations This document has no actions for IANA. Yuankui zhao Jan 1,2008 [Page 10] Internet-Draft Default gateway consideration for netlmm Jul 2007 Authors' Addresses Yuankui Zhao Shanghai Huawei Technology Co.LTD Qian Chang Building No.450 Jin Yu Road Pudong Shanghai,201206 china Phone: Email: John.zhao@huawei.com Yuankui zhao Jan 1,2008 [Page 11] Internet-Draft Default gateway consideration for netlmm Jul 2007 Full Copyright Statement Copyright (C) The IETF Trust (2007). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. 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Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). Yuankui zhao Jan 1,2008 [Page 12]