Network Working Group B. Sarikaya Internet-Draft Huawei USA Intended status: Standards Track February 25, 2013 Expires: August 29, 2013 IPv6 RA Options for Multiple Interface Next Hop Routes draft-sarikaya-mif-6man-ra-route-02 Abstract This draft defines new Router Advertisement options for configuring next hop routes on the mobile or fixed nodes. Using these options, an operator can easily configure nodes with multiple interfaces (or otherwise multi-homed) to enable them to select the routes to a destination. Each option is defined together with definitions of host and router behaviors. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on August 29, 2013. Copyright Notice Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as Sarikaya Expires August 29, 2013 [Page 1] Internet-Draft New RA Options February 2013 described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Default Route Configuration . . . . . . . . . . . . . . . . . . 4 4. Host Configuration . . . . . . . . . . . . . . . . . . . . . . 4 5. Router Configuration . . . . . . . . . . . . . . . . . . . . . 4 6. Route Prefix option . . . . . . . . . . . . . . . . . . . . . . 5 7. Next Hop Address option . . . . . . . . . . . . . . . . . . . . 5 8. Next Hop Address with Route Prefix option . . . . . . . . . . . 6 9. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 12.1. Normative References . . . . . . . . . . . . . . . . . . . 8 12.2. Informative References . . . . . . . . . . . . . . . . . . 8 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 9 Sarikaya Expires August 29, 2013 [Page 2] Internet-Draft New RA Options February 2013 1. Introduction IPv6 Neighbor Discovery and IPv6 Stateless Address Autoconfiguration protocols can be used to configure fixed and mobile nodes with various parameters related to addressing and routing [RFC4861], [RFC4862], [RFC4191]. DNS Recursive Server Addresses and Domain Name Search Lists are additional parameters that can be configured using router advertisements [RFC6106]. Router Advertisements can also be used to configure fixed and mobile nodes in multi-homed scenarios with route information and next hop address. Different scenarios exist such as the node is simultaneously connected to multiple access network of e.g. WiFi and 3G. The node may also be connected to more than one gateway. Such connectivity may be realized by means of dedicated physical or logical links that may also be shared with other users nodes such as in residential access networks. 2. 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 [RFC2119]. Sarikaya Expires August 29, 2013 [Page 3] Internet-Draft New RA Options February 2013 3. Default Route Configuration A host, usually a mobile host interested in obtaining routing information usually sends a Router Solicitation (RS) message on the link. The router, when configured to do so, provides the route information using zero, one or more Next Hop Address and Route Information options in the router advertisement (RA) messages sent in response. The route options are extensible, as well as convey detailed information for routes. RS and RA exchange is for next hop address and route information determination and not for determining the link-layer address of the router. Subsequent Neighbor Solicitation and Neighbor Advertisement exchange can be used to determine link-layer address of the router. It should be noted that the proposed options in this document will need a central site-wide configuration mechanism. The required values can not automatically be derived from routing tables. Next hop address and related route information may be provided by some other means such as directly by the next hop routers. In this document we assume that next hop routers are not able to provide this information. One solution would be to develop an inter-router protocol to instigate the next hop routers to provide this information. However, such a solution has been singled out due to the complexities involved. 4. Host Configuration Router advertisement options defined in this document are used by Type C hosts. As defined in [RFC4191] Type C host uses a Routing Table instead of a Default Router List. 5. Router Configuration The router MAY send one or more Next Hop Address options that specify the IPv6 next hop addresses. Each Next Hop Address option may be associated with zero, one or more Route Prefix options that represent the IPv6 destination prefixes reachable via the given next hop. Router includes Route Prefix option in message to indicate that given prefix is available directly on- link. Sarikaya Expires August 29, 2013 [Page 4] Internet-Draft New RA Options February 2013 Router MAY send a single Next Hop Address without any Route Prefix options. When router sends Next Hop Address option that is associated with Router Prefix option, the router MUST use Next Hop and Route Prefix option defined in Section 8. The Route Prefix MAY contain ::/0, i.e. with Prefix Length set to zero to indicate available default route. 6. Route Prefix option 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Prefix Length |Resvd|Prf|Metric| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Route Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix (Variable Length) | . . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: Route Prefix option Fields: Type: TBD. Length: The length of the option (including the Type and Length fields) in units of 8 octets. Other fields are as in [RFC4191] except: Metric Route Metric. 3-bit signed integer. The Route Metric indicates whether to prefer the next hop associated with this prefix over others, when multiple identical prefixes (for different next hops) have been received. 7. Next Hop Address option 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Next Hop Address ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: Next Hop Address option Sarikaya Expires August 29, 2013 [Page 5] Internet-Draft New RA Options February 2013 Fields: Type: TBD. Length: The length of the option (including the type and length fields) in units of 8 octets. It's value is 3. Next Hop Address: An IPv6 address that specifies IPv6 address of the next hop. It is 16 octets in length. 8. Next Hop Address with Route Prefix option 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Next Hop Address ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | Prefix Length |Resvd|Prf|Metric| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Route Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix (Variable Length) | . . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Next Hop Address with Route Prefix option Fields: Type: TBD. Length: The length of the option (including the type and length fields) in units of 8 octets. For example, the length for a prefix of length 16 is 5. Other fields are as in Section 6 and Section 7. 9. Security Considerations Neighbor Discovery is subject to attacks that cause IP packets to flow to unexpected places. Because of this, neighbor discovery messages MUST be secured, possibly using Secure Neighbor Discovery (SEND) protocol [RFC3971]. Sarikaya Expires August 29, 2013 [Page 6] Internet-Draft New RA Options February 2013 10. IANA Considerations Authors of this document request IANA to assign three new RA options: +-----------------------------------+------+ | Option Name | Type | +-----------------------------------+------+ | Route Prefix | | | Next Hop Address | | | Next Hop Address and Route Prefix | | +-----------------------------------+------+ Table 1: 11. Acknowledgements Brian Carpenter provided comments that have led to improvements in the document. We are also grateful to Zhen Cao for his comments. Sarikaya Expires August 29, 2013 [Page 7] Internet-Draft New RA Options February 2013 12. References 12.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, June 1999. [RFC3971] Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure Neighbor Discovery (SEND)", RFC 3971, March 2005. [RFC4191] Draves, R. and D. Thaler, "Default Router Preferences and More-Specific Routes", RFC 4191, November 2005. [RFC4605] Fenner, B., He, H., Haberman, B., and H. Sandick, "Internet Group Management Protocol (IGMP) / Multicast Listener Discovery (MLD)-Based Multicast Forwarding ("IGMP/MLD Proxying")", RFC 4605, August 2006. [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, September 2007. [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless Address Autoconfiguration", RFC 4862, September 2007. 12.2. Informative References [RFC6106] Jeong, J., Park, S., Beloeil, L., and S. Madanapalli, "IPv6 Router Advertisement Options for DNS Configuration", RFC 6106, November 2010. Sarikaya Expires August 29, 2013 [Page 8] Internet-Draft New RA Options February 2013 Author's Address Behcet Sarikaya Huawei USA 5340 Legacy Dr. Building 175 Plano, TX 75024 Phone: Email: sarikaya@ieee.org Sarikaya Expires August 29, 2013 [Page 9]