Network Working Group K. Leung Internet-Draft A. Patel Expires: August 12, 2005 Cisco Systems G. Tsirtsis Flarion Technologies E. Klovning Birdstep Technology ASA February 11, 2005 Mobile IPv4 Host Configuration Vendor Specific Extensions draft-leung-mip4-host-config-vse-00.txt Status of this Memo By submitting this Internet-Draft, I certify that any applicable patent or other IPR claims of which I am aware have been disclosed, and any of which I become aware will be disclosed, in accordance with RFC 3668. 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 August 12, 2005. Copyright Notice Copyright (C) The Internet Society (2005). All Rights Reserved. Abstract An IP device requires basic host configuration to be able to communicate. For example, the IP address on the interface and the DNS server for a hostname to IP address lookup. This information is configured statically or obtained dynamically using Dynamic Host Configuration Protocol (DHCP) or Point-to- Point Protocol/IP Control Leung, et al. Expires August 12, 2005 [Page 1] Internet-Draft Host Config February 2005 Protocol (PPP/IPCP). However, both DHCP and PPP/IPCP provides host configuration based on the access network. In Mobile IPv4, the registration process boots up a Mobile Node at an access network, also known as foreign network. The information to configure the host needs to be based on the home network. This document describes the extensions used to provide the base host configuration in the Registration Request and Reply messages. The content is provided for informational purpose only. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Host Configuration Extensions Summary . . . . . . . . . . . . 5 4. Host Configuration Extensions . . . . . . . . . . . . . . . . 6 4.1 Host Configuration Request Extension . . . . . . . . . . . 6 4.2 Home Network Prefix Extension . . . . . . . . . . . . . . 7 4.3 DNS Server Extension . . . . . . . . . . . . . . . . . . . 7 4.4 DHCP Server Extension . . . . . . . . . . . . . . . . . . 8 4.5 DHCP Client ID Extension . . . . . . . . . . . . . . . . . 9 4.6 Default Gateway Extension . . . . . . . . . . . . . . . . 9 4.7 DNS Suffix Extension . . . . . . . . . . . . . . . . . . . 10 4.8 Configuration URL Extension . . . . . . . . . . . . . . . 10 5. Security Considerations . . . . . . . . . . . . . . . . . . . 11 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 13 Intellectual Property and Copyright Statements . . . . . . . . 15 Leung, et al. Expires August 12, 2005 [Page 2] Internet-Draft Host Config February 2005 1. Introduction An IPv4 device requires some basic configuration to communicate with other nodes. Typically, it has an IP address for an interface and DNS server's IP address to resolve the peer's hostname to an IP address. DHCP [RFC2131] and PPP/IPCP [RFC1332] provides host configuration information on the access network interface, but this is inadequate. However, in Mobile IPv4 [RFC3344], a Mobile Node has a virtual network interface on the home network, anchored by the Home Agent. The IP address, home subnet prefix, default gateway, and home network's DNS servers are essential in the boot up of a network interface. In some cases, these are the only information needed by the Mobile Node. The Mobile IPv4 registration process provides the mechanism for a Mobile Node to boot up on a foreign network. Upon the successful registration, the Mobile Node can communicate with the Correspondent Node. The need to provide an efficient method to obtain the host configuration exists. If the Mobile Node is a DHCP client, it can obtain configuration parameters from the DHCP server in the home network after the initial registration. This document introduces the Cisco vendor specific extensions [RFC3115] to provide the means for a Mobile Node to download some fundamental configuration associated with the home network via the Home Agent. These extensions provide information for home subnet prefix, DNS server, DHCP server, DHCP client identifier, default gateway, DNS suffix, and configuration URL. The home subnet prefix allows the Mobile Node to set up the subnet mask on the virtual interface properly. The default gateway may be the Home Agent's address, but at times, that address is the tunnel endpoint on a virtual interface and not on the home subnet. In this case, the extension provides the Home Agent's address or another appropriate address to satisfy the network interface configuration on the Mobile Node. The DNS server's IP address and DNS suffix are based on the home administrative domain. The DHCP client ID and DHCP server's IP address provides information for the Mobile Node to renew its home address with the DHCP server when the Mobile Node returns home and the Home Agent is no longer maintaining the home address of the Mobile Node The configuration URL provides a convenient mechanism to download additional configuration parameters of the Mobile Nodes from a centralized repository. Leung, et al. Expires August 12, 2005 [Page 3] Internet-Draft Host Config February 2005 2. Terminology The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119. Leung, et al. Expires August 12, 2005 [Page 4] Internet-Draft Host Config February 2005 3. Host Configuration Extensions Summary The following Cisco vendor specific extensions provide the host configuration for a Mobile Node. o Host Configuration Request * Request for host configuration information from the Mobile Node to the Home Agent. o Home Network Prefix * The subnet prefix on the home network. o Default Gateway * The default gateway's IP address on the home network. o DNS Server * The DNS server's IP address in the home network. o DNS Suffix * The DNS suffix for hostname resolution in the home network. o DHCP Client ID * The DHCP Client-ID used to obtain the IP address. When the Mobile Node returns home and is responsible for managing its own address, if the home address was assigned using DHCP server, this options maps to the client identifier option as defined in section 9.14 of [RFC2132] and referenced in [RFC2131]. o DHCP Server * The DHCP server's IP address in the home network. o Configuration URL * The URL for the Moible Node to download configuration parameters from a server. When the Mobile Node needs to obtain its host configuration, the Host Configuration Request VSE is appended to the Registration Request. This VSE indicates to the Home Agent that either all or selected host configuration VSEs need to be appended to the Registration Reply. The VSEs are authenticated as part of the registration message using any of the authentication mechanism defined for Mobile IP ([RFC3344], [RFC3012]). This message MAY contain extensions defined in Mobile IP, including vendor specific extensions [RFC3115]. Leung, et al. Expires August 12, 2005 [Page 5] Internet-Draft Host Config February 2005 4. Host Configuration Extensions The host configuration extensions are based on normal vendor specific extension type which is skippable during registration processing. The format is shown below. The Vendor-NVSE-Value contains the subtype fields. 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 | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Vendor/Org-ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Vendor-NVSE-Type | Vendor-NVSE-Value ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: 134 Length: Indicates the length (in bytes) of the data field within this extension, excluding the Type and Length fields. Reserved: Reserved for future use. To be set to 0 while sending, ignored on reception. Vendor-NVSE-Type: 9 (cisco) Vendor-NVSE-Value: Format is shown below for each subtype. 4.1 Host Configuration Request Extension This format of the Host Configuration Request extension is shown below. Leung, et al. Expires August 12, 2005 [Page 6] Internet-Draft Host Config February 2005 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-Type | Selector | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Sub-Type: 0 Selector: 0 indicates all host configuration available to the HA is requested by the Mobile Node. 4.2 Home Network Prefix Extension This format of the Home Network Prefix extension is shown below. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-Type | Prefix Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Sub-Type: 1 Prefix Length: The number of bits in the home subnet prefix. 4.3 DNS Server Extension This format of the DNS Server extension is shown below. Leung, et al. Expires August 12, 2005 [Page 7] Internet-Draft Host Config February 2005 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-Type | Primary DNS Server +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . | Secondary DNS Server +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Sub Type: 2 Primary DNS Server: The IP address of the primary DNS server. Secondary DNS Server: The IP address of the secondary DNS server. 4.4 DHCP Server Extension This format of the DHCP Server extension is shown below. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-Type | DHCP Server +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Sub-Type: 3 DHCP Server: The IP address of the DHCP server. Leung, et al. Expires August 12, 2005 [Page 8] Internet-Draft Host Config February 2005 4.5 DHCP Client ID Extension This format of the DHCP client id extension is shown below. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-Type | Client ID . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Sub-Type: 4 Client ID: DHCP servers use this value to index their database of address bindings. This value is expected to be unique for all clients in an administrative domain. The size of field is between 2 and 255 octets. 4.6 Default Gateway Extension This format of the Default Gateway extension is shown below. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-Type | Default Gateway +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Sub-Type: 5 Default Gateway: The IP address of the default gateway for the Mobile Node on the home network. Leung, et al. Expires August 12, 2005 [Page 9] Internet-Draft Host Config February 2005 4.7 DNS Suffix Extension This format of the DNS Suffix extension is shown below. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-Type | DNS Suffix . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Sub-Type: 6 DNS Suffix: The DNS suffix to be appended to the name of Mobile Node when completing its fully qualified domain name (FQDN). The size of field is between 1 and 246 octets. 4.8 Configuration URL Extension This format of the Configuration URL extension is shown below. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-Type | URL String . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Sub-Type: 7 URL String: The Mobile Node can retrieve configuration parameters via the URL. The URL is atmost 246 bytes in length. Leung, et al. Expires August 12, 2005 [Page 10] Internet-Draft Host Config February 2005 5. Security Considerations The host configuration extensions are protected by the same method as any Mobile IP extension. The Configuration URL extension may trigger the Mobile Node to download the configuration parameters from a server. The protection of the data transfer is outside the scope of this document. Leung, et al. Expires August 12, 2005 [Page 11] Internet-Draft Host Config February 2005 6. IANA Considerations This is an information draft. No IANA actions required. Leung, et al. Expires August 12, 2005 [Page 12] Internet-Draft Host Config February 2005 7. Acknowledgements The authors would like to acknowledge Jayshree Bharatia, Kuntal Chowdhury, Avi Lior, and Lila Madour for their contributions to Mobile IPv4 Extension for Configuration Options Exchange draft, draft-bharatia-mobileip-gen-mipv4-ext-02.txt. 8 References [RFC1332] McGregor, G., "The PPP Internet Protocol Control Protocol (IPCP)", RFC 1332, May 1992. [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor Extensions", RFC 2132, March 1997. [RFC3012] Perkins, C. and P. Calhoun, "Mobile IPv4 Challenge/ Response Extensions", RFC 3012, November 2000. [RFC3115] Dommety, G. and K. Leung, "Mobile IP Vendor/ Organization-Specific Extensions", RFC 3115, April 2001. [RFC3344] Perkins, C., "IP Mobility Support for IPv4", RFC 3344, August 2002. Authors' Addresses Kent Leung Cisco Systems 170 W. Tasman Drive San Jose, CA 95134 US Phone: +1 408-526-5030 EMail: kleung@cisco.com Alpesh Patel Cisco Systems 170 W. Tasman Drive San Jose, CA 95134 US Phone: +1 408-853-9580 EMail: alpesh@cisco.com Leung, et al. Expires August 12, 2005 [Page 13] Internet-Draft Host Config February 2005 George Flarion Technologies Bedminster One 135 Route 202/206 South Bedminster, NJ 07921 US Phone: EMail: g.tsirtsis@flarion.com Espen Birdstep Technology ASA Bryggegata 7 Oslo, 0250 Norway Phone: +47 95 20 26 29 EMail: espen@birdstep.com Leung, et al. Expires August 12, 2005 [Page 14] Internet-Draft Host Config February 2005 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. 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. 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Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Leung, et al. Expires August 12, 2005 [Page 15]