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diff --git a/doc/rfc/rfc5204.txt b/doc/rfc/rfc5204.txt new file mode 100644 index 0000000..7bea1a8 --- /dev/null +++ b/doc/rfc/rfc5204.txt @@ -0,0 +1,843 @@ + + + + + + +Network Working Group J. Laganier +Request for Comments: 5204 DoCoMo Euro-Labs +Category: Experimental L. Eggert + Nokia + April 2008 + + + Host Identity Protocol (HIP) Rendezvous Extension + +Status of This Memo + + This memo defines an Experimental Protocol for the Internet + community. It does not specify an Internet standard of any kind. + Discussion and suggestions for improvement are requested. + Distribution of this memo is unlimited. + +Abstract + + This document defines a rendezvous extension for the Host Identity + Protocol (HIP). The rendezvous extension extends HIP and the HIP + registration extension for initiating communication between HIP nodes + via HIP rendezvous servers. Rendezvous servers improve reachability + and operation when HIP nodes are multi-homed or mobile. + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Laganier & Eggert Experimental [Page 1] + +RFC 5204 HIP Rendezvous Extension April 2008 + + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 3. Overview of Rendezvous Server Operation . . . . . . . . . . . 4 + 3.1. Diagram Notation . . . . . . . . . . . . . . . . . . . . . 5 + 3.2. Rendezvous Client Registration . . . . . . . . . . . . . . 6 + 3.3. Relaying the Base Exchange . . . . . . . . . . . . . . . . 6 + 4. Rendezvous Server Extensions . . . . . . . . . . . . . . . . . 7 + 4.1. RENDEZVOUS Registration Type . . . . . . . . . . . . . . . 7 + 4.2. Parameter Formats and Processing . . . . . . . . . . . . . 8 + 4.2.1. RVS_HMAC Parameter . . . . . . . . . . . . . . . . . . 8 + 4.2.2. FROM Parameter . . . . . . . . . . . . . . . . . . . . 9 + 4.2.3. VIA_RVS Parameter . . . . . . . . . . . . . . . . . . 10 + 4.3. Modified Packets Processing . . . . . . . . . . . . . . . 10 + 4.3.1. Processing Outgoing I1 Packets . . . . . . . . . . . . 10 + 4.3.2. Processing Incoming I1 Packets . . . . . . . . . . . . 11 + 4.3.3. Processing Outgoing R1 Packets . . . . . . . . . . . . 11 + 4.3.4. Processing Incoming R1 Packets . . . . . . . . . . . . 11 + 5. Security Considerations . . . . . . . . . . . . . . . . . . . 12 + 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 + 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 13 + 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 + 8.1. Normative References . . . . . . . . . . . . . . . . . . . 13 + 8.2. Informative References . . . . . . . . . . . . . . . . . . 14 + + + + + + + + + + + + + + + + + + + + + + + + + + +Laganier & Eggert Experimental [Page 2] + +RFC 5204 HIP Rendezvous Extension April 2008 + + +1. Introduction + + The Host Identity Protocol (HIP) Architecture [RFC4423] introduces + the rendezvous mechanism to help a HIP node to contact a frequently + moving HIP node. The rendezvous mechanism involves a third party, + the rendezvous server (RVS), which serves as an initial contact point + ("rendezvous point") for its clients. The clients of an RVS are HIP + nodes that use the HIP Registration Extension [RFC5203] to register + their HIT->IP address mappings with the RVS. After this + registration, other HIP nodes can initiate a base exchange using the + IP address of the RVS instead of the current IP address of the node + they attempt to contact. Essentially, the clients of an RVS become + reachable at the RVS's IP address. Peers can initiate a HIP base + exchange with the IP address of the RVS, which will relay this + initial communication such that the base exchange may successfully + complete. + +2. Terminology + + This section defines terms used throughout the remainder of this + specification. + + 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 RFC 2119 [RFC2119]. + + In addition to the terminology defined in the HIP specification + [RFC5201] and the HIP Registration Extension [RFC5203], this document + defines and uses the following terms: + + Rendezvous Service + A HIP service provided by a rendezvous server to its rendezvous + clients. The rendezvous server offers to relay some of the + arriving base exchange packets between the initiator and + responder. + + Rendezvous Server (RVS) + A HIP registrar providing rendezvous service. + + Rendezvous Client + A HIP requester that has registered for rendezvous service at a + rendezvous server. + + Rendezvous Registration + A HIP registration for rendezvous service, established between a + rendezvous server and a rendezvous client. + + + + + +Laganier & Eggert Experimental [Page 3] + +RFC 5204 HIP Rendezvous Extension April 2008 + + +3. Overview of Rendezvous Server Operation + + Figure 1 shows a simple HIP base exchange without a rendezvous + server, in which the initiator initiates the exchange directly with + the responder by sending an I1 packet to the responder's IP address, + as per the HIP specification [RFC5201]. + + +-----+ +-----+ + | |-------I1------>| | + | I |<------R1-------| R | + | |-------I2------>| | + | |<------R2-------| | + +-----+ +-----+ + + Figure 1: HIP base exchange without rendezvous server. + + The End-Host Mobility and Multihoming with the Host Identity Protocol + specification [RFC5206] allows a HIP node to notify its peers about + changes in its set of IP addresses. This specification presumes + initial reachability of the two nodes with respect to each other. + + However, such a HIP node MAY also want to be reachable to other + future correspondent peers that are unaware of its location change. + The HIP Architecture [RFC4423] introduces rendezvous servers with + whom a HIP node MAY register its host identity tags (HITs) and + current IP addresses. An RVS relays HIP packets arriving for these + HITs to the node's registered IP addresses. When a HIP node has + registered with an RVS, it SHOULD record the IP address of its RVS in + its DNS record, using the HIP DNS resource record type defined in the + HIP DNS Extension [RFC5205]. + + +-----+ + +--I1--->| RVS |---I1--+ + | +-----+ | + | v + +-----+ +-----+ + | |<------R1-------| | + | I |-------I2------>| R | + | |<------R2-------| | + +-----+ +-----+ + + Figure 2: HIP base exchange with a rendezvous server. + + Figure 2 shows a HIP base exchange involving a rendezvous server. It + is assumed that HIP node R previously registered its HITs and current + IP addresses with the RVS, using the HIP Registration Extension + [RFC5203]. When the initiator I tries to establish contact with the + + + + +Laganier & Eggert Experimental [Page 4] + +RFC 5204 HIP Rendezvous Extension April 2008 + + + responder R, it must send the I1 of the base exchange either to one + of R's IP addresses (if known via DNS or other means) or to one of + R's rendezvous servers. Here, I obtains the IP address of R's + rendezvous server from R's DNS record and then sends the I1 packet of + the HIP base exchange to RVS. RVS, noticing that the HIT contained + in the arriving I1 packet is not one of its own, MUST check its + current registrations to determine if it needs to relay the packets. + Here, it determines that the HIT belongs to R and then relays the I1 + packet to the registered IP address. R then completes the base + exchange without further assistance from RVS by sending an R1 + directly to the I's IP address, as obtained from the I1 packet. In + this specification, the client of the RVS is always the responder. + However, there might be reasons to allow a client to initiate a base + exchange through its own RVS, like NAT and firewall traversal. This + specification does not address such scenarios, which should be + specified in other documents. + +3.1. Diagram Notation + + Notation Significance + -------- ------------ + + I, R I and R are the respective source and destination IP + addresses in the IP header. + + HIT-I, HIT-R HIT-I and HIT-R are the initiator's and the + responder's HITs in the packet, respectively. + + REG_REQ A REG_REQUEST parameter is present in the HIP header. + + REG_RES A REG_RESPONSE parameter is present in the HIP header. + + FROM:I A FROM parameter containing the IP address I is + present in the HIP header. + + RVS_HMAC An RVS_HMAC parameter containing an HMAC keyed with the + appropriate registration key is present in the HIP + header. + + VIA:RVS A VIA_RVS parameter containing the IP address RVS of a + rendezvous server is present in the HIP header. + + + + + + + + + + +Laganier & Eggert Experimental [Page 5] + +RFC 5204 HIP Rendezvous Extension April 2008 + + +3.2. Rendezvous Client Registration + + Before a rendezvous server starts to relay HIP packets to a + rendezvous client, the rendezvous client needs to register with it to + receive rendezvous service by using the HIP Registration Extension + [RFC5203] as illustrated in the following schema: + + +-----+ +-----+ + | | I1 | | + | |--------------------------->| | + | |<---------------------------| | + | I | R1(REG_INFO) | RVS | + | | I2(REG_REQ) | | + | |--------------------------->| | + | |<---------------------------| | + | | R2(REG_RES) | | + +-----+ +-----+ + + Rendezvous client registering with a rendezvous server. + +3.3. Relaying the Base Exchange + + If a HIP node and one of its rendezvous servers have a rendezvous + registration, the rendezvous servers relay inbound I1 packets (that + contain one of the client's HITs) by rewriting the IP header. They + replace the destination IP address of the I1 packet with one of the + IP addresses of the owner of the HIT, i.e., the rendezvous client. + They MUST also recompute the IP checksum accordingly. + + Because of egress filtering on the path from the RVS to the client + [RFC2827][RFC3013], a HIP rendezvous server SHOULD replace the source + IP address, i.e., the IP address of I, with one of its own IP + addresses. The replacement IP address SHOULD be chosen according to + relevant IPv4 and IPv6 specifications [RFC1122][RFC3484]. Because + this replacement conceals the initiator's IP address, the RVS MUST + append a FROM parameter containing the original source IP address of + the packet. This FROM parameter MUST be integrity protected by an + RVS_HMAC keyed with the corresponding rendezvous registration + integrity key [RFC5203]. + + + + + + + + + + + + +Laganier & Eggert Experimental [Page 6] + +RFC 5204 HIP Rendezvous Extension April 2008 + + + I1(RVS, R, HIT-I, HIT-R + I1(I, RVS, HIT-I, HIT-R) +---------+ FROM:I, RVS_HMAC) + +----------------------->| |--------------------+ + | | RVS | | + | | | | + | +---------+ | + | V + +-----+ R1(R, I, HIT-R, HIT-I, VIA:RVS) +-----+ + | |<---------------------------------------------| | + | | | | + | I | I2(I, R, HIT-I, HIT-R) | R | + | |--------------------------------------------->| | + | |<---------------------------------------------| | + +-----+ R2(R, I, HIT-R, HIT-I) +-----+ + + Rendezvous server rewriting IP addresses. + + This modification of HIP packets at a rendezvous server can be + problematic because the HIP protocol uses integrity checks. Because + the I1 does not include HMAC or SIGNATURE parameters, these two end- + to-end integrity checks are unaffected by the operation of rendezvous + servers. + + The RVS SHOULD verify the checksum field of an I1 packet before doing + any modifications. After modification, it MUST recompute the + checksum field using the updated HIP header, which possibly included + new FROM and RVS_HMAC parameters, and a pseudo-header containing the + updated source and destination IP addresses. This enables the + responder to validate the checksum of the I1 packet "as is", without + having to parse any FROM parameters. + +4. Rendezvous Server Extensions + + This section describes extensions to the HIP Registration Extension + [RFC5203], allowing a HIP node to register with a rendezvous server + for rendezvous service and notify the RVS aware of changes to its + current location. It also describes an extension to the HIP + specification [RFC5201] itself, allowing establishment of HIP + associations via one or more HIP rendezvous server(s). + +4.1. RENDEZVOUS Registration Type + + This specification defines an additional registration for the HIP + Registration Extension [RFC5203] that allows registering with a + rendezvous server for rendezvous service. + + + + + + +Laganier & Eggert Experimental [Page 7] + +RFC 5204 HIP Rendezvous Extension April 2008 + + + Number Registration Type + ------ ----------------- + 1 RENDEZVOUS + +4.2. Parameter Formats and Processing + +4.2.1. RVS_HMAC Parameter + + The RVS_HMAC is a non-critical parameter whose only difference with + the HMAC parameter defined in the HIP specification [RFC5201] is its + "type" code. This change causes it to be located after the FROM + parameter (as opposed to the HMAC): + + Type 65500 + Length Variable. Length in octets, excluding Type, Length, and + Padding. + HMAC HMAC computed over the HIP packet, excluding the + RVS_HMAC parameter and any following parameters. The + HMAC is keyed with the appropriate HIP integrity key + (HIP-lg or HIP-gl) established when rendezvous + registration happened. The HIP "checksum" field MUST be set + to zero, and the HIP header length in the HIP common header + MUST be calculated not to cover any excluded parameter + when the HMAC is calculated. The size of the + HMAC is the natural size of the hash computation + output depending on the used hash function. + + To allow a rendezvous client and its RVS to verify the integrity of + packets flowing between them, both SHOULD protect packets with an + added RVS_HMAC parameter keyed with the HIP-lg or HIP-gl integrity + key established while registration occurred. A valid RVS_HMAC SHOULD + be present on every packet flowing between a client and a server and + MUST be present when a FROM parameter is processed. + + + + + + + + + + + + + + + + + + +Laganier & Eggert Experimental [Page 8] + +RFC 5204 HIP Rendezvous Extension April 2008 + + +4.2.2. FROM Parameter + + 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 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | Address | + | | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Type 65498 + Length 16 + Address An IPv6 address or an IPv4-in-IPv6 format IPv4 address. + + A rendezvous server MUST add a FROM parameter containing the original + source IP address of a HIP packet whenever the source IP address in + the IP header is rewritten. If one or more FROM parameters are + already present, the new FROM parameter MUST be appended after the + existing ones. + + Whenever an RVS inserts a FROM parameter, it MUST insert an RVS_HMAC + protecting the packet integrity, especially the IP address included + in the FROM parameter. + + + + + + + + + + + + + + + + + + + + + + + + + +Laganier & Eggert Experimental [Page 9] + +RFC 5204 HIP Rendezvous Extension April 2008 + + +4.2.3. VIA_RVS Parameter + + 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 | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | Address | + | | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + . . . + . . . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | Address | + | | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Type 65502 + Length Variable + Address An IPv6 address or an IPv4-in-IPv6 format IPv4 address. + + After the responder receives a relayed I1 packet, it can begin to + send HIP packets addressed to the initiator's IP address, without + further assistance from an RVS. For debugging purposes, it MAY + include a subset of the IP addresses of its RVSs in some of these + packets. When a responder does so, it MUST append a newly created + VIA_RVS parameter at the end of the HIP packet. The main goal of + using the VIA_RVS parameter is to allow operators to diagnose + possible issues encountered while establishing a HIP association via + an RVS. + +4.3. Modified Packets Processing + + The following subsections describe the differences of processing of + I1 and R1 while a rendezvous server is involved in the base exchange. + +4.3.1. Processing Outgoing I1 Packets + + An initiator SHOULD NOT send an opportunistic I1 with a NULL + destination HIT to an IP address that is known to be a rendezvous + server address, unless it wants to establish a HIP association with + the rendezvous server itself and does not know its HIT. + + + + + +Laganier & Eggert Experimental [Page 10] + +RFC 5204 HIP Rendezvous Extension April 2008 + + + When an RVS rewrites the source IP address of an I1 packet due to + egress filtering, it MUST add a FROM parameter to the I1 that + contains the initiator's source IP address. This FROM parameter MUST + be protected by an RVS_HMAC keyed with the integrity key established + at rendezvous registration. + +4.3.2. Processing Incoming I1 Packets + + When a rendezvous server receives an I1 whose destination HIT is not + its own, it consults its registration database to find a registration + for the rendezvous service established by the HIT owner. If it finds + an appropriate registration, it relays the packet to the registered + IP address. If it does not find an appropriate registration, it + drops the packet. + + A rendezvous server SHOULD interpret any incoming opportunistic I1 + (i.e., an I1 with a NULL destination HIT) as an I1 addressed to + itself and SHOULD NOT attempt to relay it to one of its clients. + + When a rendezvous client receives an I1, it MUST validate any present + RVS_HMAC parameter. If the RVS_HMAC cannot be verified, the packet + SHOULD be dropped. If the RVS_HMAC cannot be verified and a FROM + parameter is present, the packet MUST be dropped. + + A rendezvous client acting as responder SHOULD drop opportunistic I1s + that include a FROM parameter, because this indicates that the I1 has + been relayed. + +4.3.3. Processing Outgoing R1 Packets + + When a responder replies to an I1 relayed via an RVS, it MUST append + to the regular R1 header a VIA_RVS parameter containing the IP + addresses of the traversed RVSs. + +4.3.4. Processing Incoming R1 Packets + + The HIP specification [RFC5201] mandates that a system receiving an + R1 MUST first check to see if it has sent an I1 to the originator of + the R1 (i.e., the system is in state I1-SENT). When the R1 is + replying to a relayed I1, this check SHOULD be based on HITs only. + In case the IP addresses are also checked, then the source IP address + MUST be checked against the IP address included in the VIA_RVS + parameter. + + + + + + + + +Laganier & Eggert Experimental [Page 11] + +RFC 5204 HIP Rendezvous Extension April 2008 + + +5. Security Considerations + + This section discusses the known threats introduced by these HIP + extensions and the implications on the overall security of HIP. In + particular, it argues that the extensions described in this document + do not introduce additional threats to the Host Identity Protocol. + + It is difficult to encompass the whole scope of threats introduced by + rendezvous servers because their presence has implications both at + the IP and HIP layers. In particular, these extensions might allow + for redirection, amplification, and reflection attacks at the IP + layer, as well as attacks on the HIP layer itself, for example, man- + in-the-middle attacks against the HIP base exchange. + + If an initiator has a priori knowledge of the responder's host + identity when it first contacts the responder via an RVS, it has a + means to verify the signatures in the HIP base exchange, which + protects against man-in-the-middle attacks. + + If an initiator does not have a priori knowledge of the responder's + host identity (so-called "opportunistic initiators"), it is almost + impossible to defend the HIP exchange against these attacks, because + the public keys exchanged cannot be authenticated. The only approach + would be to mitigate hijacking threats on HIP state by requiring an + R1 answering an opportunistic I1 to come from the same IP address + that originally sent the I1. This procedure retains a level of + security that is equivalent to what exists in the Internet today. + + However, for reasons of simplicity, this specification does not allow + the establishment of a HIP association via a rendezvous server in an + opportunistic manner. + +6. IANA Considerations + + This section is to be interpreted according to the Guidelines for + Writing an IANA Considerations Section in RFCs [RFC2434]. + + This document updates the IANA Registry for HIP Parameters Types by + assigning new HIP Parameter Types values for the new HIP Parameters + defined in Section 4.2: + + o RVS_HMAC (defined in Section 4.2.1) + + o FROM (defined in Section 4.2.2) + + o VIA_RVS (defined in Section 4.2.3) + + + + + +Laganier & Eggert Experimental [Page 12] + +RFC 5204 HIP Rendezvous Extension April 2008 + + + This document defines an additional registration for the HIP + Registration Extension [RFC5203] that allows registering with a + rendezvous server for rendezvous service. + + Number Registration Type + ------ ----------------- + 1 RENDEZVOUS + +7. Acknowledgments + + The following people have provided thoughtful and helpful discussions + and/or suggestions that have improved this document: Marcus Brunner, + Tom Henderson, Miika Komu, Mika Kousa, Pekka Nikander, Justino + Santos, Simon Schuetz, Tim Shepard, Kristian Slavov, Martin + Stiemerling, and Juergen Quittek. + +8. References + +8.1. Normative References + + [RFC1122] Braden, R., "Requirements for Internet Hosts - + Communication Layers", STD 3, RFC 1122, October 1989. + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an + IANA Considerations Section in RFCs", BCP 26, RFC 2434, + October 1998. + + [RFC3484] Draves, R., "Default Address Selection for Internet + Protocol version 6 (IPv6)", RFC 3484, February 2003. + + [RFC5201] Moskowitz, R., Nikander, P., Jokela, P., Ed., and T. + Henderson, "Host Identity Protocol", RFC 5201, April 2008. + + [RFC5203] Laganier, J., Koponen, T., and L. Eggert, "Host Identity + Protocol (HIP) Registration Extension", RFC 5203, + April 2008. + + [RFC5205] Nikander, P. and J. Laganier, "Host Identity Protocol + (HIP) Domain Name System (DNS) Extensions", RFC 5205, + April 2008. + + + + + + + + +Laganier & Eggert Experimental [Page 13] + +RFC 5204 HIP Rendezvous Extension April 2008 + + +8.2. Informative References + + [RFC2827] Ferguson, P. and D. Senie, "Network Ingress Filtering: + Defeating Denial of Service Attacks which employ IP Source + Address Spoofing", BCP 38, RFC 2827, May 2000. + + [RFC3013] Killalea, T., "Recommended Internet Service Provider + Security Services and Procedures", BCP 46, RFC 3013, + November 2000. + + [RFC4423] Moskowitz, R. and P. Nikander, "Host Identity Protocol + (HIP) Architecture", RFC 4423, May 2006. + + [RFC5206] Henderson, T., Ed., "End-Host Mobility and Multihoming + with the Host Identity Protocol", RFC 5206, April 2008. + +Authors' Addresses + + Julien Laganier + DoCoMo Communications Laboratories Europe GmbH + Landsberger Strasse 312 + Munich 80687 + Germany + + Phone: +49 89 56824 231 + EMail: julien.ietf@laposte.net + URI: http://www.docomolab-euro.com/ + + + Lars Eggert + Nokia Research Center + P.O. Box 407 + Nokia Group 00045 + Finland + + Phone: +358 50 48 24461 + EMail: lars.eggert@nokia.com + URI: http://research.nokia.com/people/lars_eggert/ + + + + + + + + + + + + + +Laganier & Eggert Experimental [Page 14] + +RFC 5204 HIP Rendezvous Extension April 2008 + + +Full Copyright Statement + + Copyright (C) The IETF Trust (2008). + + 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. + + This document and the information contained herein are provided on an + "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS + OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND + THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS + OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF + THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED + WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Intellectual Property + + 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. + + 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. + + + + + + + + + + + + +Laganier & Eggert Experimental [Page 15] + |