From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc5072.txt | 899 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 899 insertions(+) create mode 100644 doc/rfc/rfc5072.txt (limited to 'doc/rfc/rfc5072.txt') diff --git a/doc/rfc/rfc5072.txt b/doc/rfc/rfc5072.txt new file mode 100644 index 0000000..c384629 --- /dev/null +++ b/doc/rfc/rfc5072.txt @@ -0,0 +1,899 @@ + + + + + + +Network Working Group S. Varada, Ed. +Request for Comments: 5072 Transwitch +Obsoletes: 2472 D. Haskins +Category: Standards Track E. Allen + September 2007 + + + IP Version 6 over PPP + +Status of This Memo + + This document specifies an Internet standards track protocol for the + Internet community, and requests discussion and suggestions for + improvements. Please refer to the current edition of the "Internet + Official Protocol Standards" (STD 1) for the standardization state + and status of this protocol. Distribution of this memo is unlimited. + +Abstract + + The Point-to-Point Protocol (PPP) provides a standard method of + encapsulating network-layer protocol information over point-to-point + links. PPP also defines an extensible Link Control Protocol, and + proposes a family of Network Control Protocols (NCPs) for + establishing and configuring different network-layer protocols. + + This document defines the method for sending IPv6 packets over PPP + links, the NCP for establishing and configuring the IPv6 over PPP, + and the method for forming IPv6 link-local addresses on PPP links. + + It also specifies the conditions for performing Duplicate Address + Detection on IPv6 global unicast addresses configured for PPP links + either through stateful or stateless address autoconfiguration. + + This document obsoletes RFC 2472. + + + + + + + + + + + + + + + + + +Varada, et al. Standards Track [Page 1] + +RFC 5072 IP Version 6 over PPP September 2007 + + +Table of Contents + + 1. Introduction ....................................................2 + 1.1. Specification of Requirements ..............................3 + 2. Sending IPv6 Datagrams ..........................................3 + 3. A PPP Network Control Protocol for IPv6 .........................3 + 4. IPV6CP Configuration Options ....................................4 + 4.1. Interface Identifier .......................................4 + 5. Stateless Autoconfiguration and Link-Local Addresses ............9 + 6. Security Considerations ........................................11 + 7. IANA Considerations ............................................11 + 8. Acknowledgments ................................................11 + 9. References .....................................................12 + 9.1. Normative References ......................................12 + 9.2. Informative references ....................................12 + Appendix A: Global Scope Addresses................................14 + Appendix B: Changes from RFC-2472.................................14 + +1. Introduction + + PPP has three main components: + + 1) A method for encapsulating datagrams over serial links. + + 2) A Link Control Protocol (LCP) for establishing, configuring, and + testing the data-link connection. + + 3) A family of Network Control Protocols (NCPs) for establishing and + configuring different network-layer protocols. + + In order to establish communications over a point-to-point link, each + end of the PPP link must first send LCP packets to configure and test + the data link. After the link has been established and optional + facilities have been negotiated as needed by the LCP, PPP must send + NCP packets to choose and configure one or more network-layer + protocols. Once each of the chosen network-layer protocols has been + configured, datagrams from each network-layer protocol can be sent + over the link. + + In this document, the NCP for establishing and configuring the IPv6 + over PPP is referred to as the IPv6 Control Protocol (IPV6CP). + + The link will remain configured for communications until explicit LCP + or NCP packets close the link down, or until some external event + occurs (power failure at the other end, carrier drop, etc.). + + This document obsoletes the earlier specification from RFC 2472 [7]. + Changes from RFC 2472 are listed in Appendix B. + + + +Varada, et al. Standards Track [Page 2] + +RFC 5072 IP Version 6 over PPP September 2007 + + +1.1. Specification of Requirements + + In this document, several words are used to signify the requirements + of the 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 [6]. + +2. Sending IPv6 Datagrams + + Before any IPv6 packets may be communicated, PPP MUST reach the + network-layer protocol phase, and the IPv6 Control Protocol MUST + reach the Opened state. + + Exactly one IPv6 packet is encapsulated in the Information field of + PPP Data Link Layer frames where the Protocol field indicates Type + hex 0057 (Internet Protocol Version 6). + + The maximum length of an IPv6 packet transmitted over a PPP link is + the same as the maximum length of the Information field of a PPP data + link layer frame. PPP links supporting IPv6 MUST allow the + information field to be at least as large as the minimum link MTU + size required for IPv6 [2]. + +3. A PPP Network Control Protocol for IPv6 + + The IPv6 Control Protocol (IPV6CP) is responsible for configuring, + enabling, and disabling the IPv6 protocol modules on both ends of the + point-to-point link. IPV6CP uses the same packet exchange mechanism + as the LCP. IPV6CP packets may not be exchanged until PPP has + reached the network-layer protocol phase. IPV6CP packets that are + received before this phase is reached should be silently discarded. + + The IPv6 Control Protocol is exactly the same as the LCP [1] with the + following exceptions: + + Data Link Layer Protocol Field + + Exactly one IPV6CP packet is encapsulated in the Information + field of PPP Data Link Layer frames where the Protocol field + indicates type hex 8057 (IPv6 Control Protocol). + + + + + + + + + +Varada, et al. Standards Track [Page 3] + +RFC 5072 IP Version 6 over PPP September 2007 + + + Code field + + Only Codes 1 through 7 (Configure-Request, Configure-Ack, + Configure-Nak, Configure-Reject, Terminate-Request, Terminate- + Ack and Code-Reject) are used. Other Codes should be treated + as unrecognized and should result in Code-Rejects. + + Timeouts + + IPV6CP packets may not be exchanged until PPP has reached the + network-layer protocol phase. An implementation should be + prepared to wait for Authentication and Link Quality + Determination to finish before timing out waiting for a + Configure-Ack or other response. It is suggested that an + implementation give up only after user intervention or a + configurable amount of time. + + Configuration Option Types + + IPV6CP has a distinct set of Configuration Options. + +4. IPV6CP Configuration Options + + IPV6CP Configuration Options allow negotiation of desirable IPv6 + parameters. IPV6CP uses the same Configuration Option format defined + for LCP [1] but with a separate set of Options. If a Configuration + Option is not included in a Configure-Request packet, the default + value for that Configuration Option is assumed. + + Up-to-date values of the IPV6CP Option Type field are specified in + the online database of "Assigned Numbers" maintained at IANA [9]. + The current value assignment is as follows: + + 1 Interface-Identifier + + The only IPV6CP option defined in this document is the interface + identifier. Any other IPV6CP configuration options that can be + defined over time are to be defined in separate documents. + +4.1. Interface Identifier + + Description + + This Configuration Option provides a way to negotiate a unique, 64- + bit interface identifier to be used for the address autoconfiguration + [3] at the local end of the link (see Section 5). A Configure- + Request MUST contain exactly one instance of the interface-identifier + option [1]. The interface identifier MUST be unique within the PPP + + + +Varada, et al. Standards Track [Page 4] + +RFC 5072 IP Version 6 over PPP September 2007 + + + link; i.e., upon completion of the negotiation, different interface- + identifier values are to be selected for the ends of the PPP link. + The interface identifier may also be unique over a broader scope. + + Before this Configuration Option is requested, an implementation + chooses its tentative interface identifier. The non-zero value of + the tentative interface identifier SHOULD be chosen such that the + value is unique to the link and, preferably, consistently + reproducible across initializations of the IPV6CP finite state + machine (administrative Close and reOpen, reboots, etc.). The + rationale for preferring a consistently reproducible unique interface + identifier to a completely random interface identifier is to provide + stability to global scope addresses (see Appendix A) that can be + formed from the interface identifier. + + Assuming that interface identifier bits are numbered from 0 to 63 in + canonical bit order, where the most significant bit is the bit number + 0, the bit number 6 is the "u" bit (universal/local bit in IEEE + EUI-64 [4] terminology), which indicates whether or not the interface + identifier is based on a globally unique IEEE identifier (EUI-48 or + EUI-64 [4])(see case 1 below). It is set to one (1) if a globally + unique IEEE identifier is used to derive the interface identifier, + and it is set to zero (0) otherwise. + + The following are methods for choosing the tentative interface + identifier in the preference order: + + 1) If an IEEE global identifier (EUI-48 or EUI-64) is available + anywhere on the node, it should be used to construct the tentative + interface identifier due to its uniqueness properties. When + extracting an IEEE global identifier from another device on the + node, care should be taken that the extracted identifier is + presented in canonical ordering [14]. + + The only transformation from an EUI-64 identifier is to invert the + "u" bit (universal/local bit in IEEE EUI-64 terminology). + + For example, for a globally unique EUI-64 identifier of the form: + + most-significant least-significant + bit bit + |0 1|1 3|3 4|4 6| + |0 5|6 1|2 7|8 3| + +----------------+----------------+----------------+----------------+ + + |cccccc0gcccccccc|cccccccceeeeeeee|eeeeeeeeeeeeeeee|eeeeeeeeeeeeeeee| + +----------------+----------------+----------------+----------------+ + + + + +Varada, et al. Standards Track [Page 5] + +RFC 5072 IP Version 6 over PPP September 2007 + + + where "c" are the bits of the assigned company_id, "0" is the + value of the universal/local bit to indicate global scope, "g" is + the group/individual bit, and "e" are the bits of the extension + identifier, the IPv6 interface identifier would be of the form: + + most-significant least-significant + bit bit + |0 1|1 3|3 4|4 6| + |0 5|6 1|2 7|8 3| + +----------------+----------------+----------------+----------------+ + + |cccccc1gcccccccc|cccccccceeeeeeee|eeeeeeeeeeeeeeee|eeeeeeeeeeeeeeee| + +----------------+----------------+----------------+----------------+ + + The only change is inverting the value of the universal/local bit. + + In the case of a EUI-48 identifier, it is first converted to the + EUI-64 format by inserting two bytes, with hexa-decimal values of + 0xFF and 0xFE, in the middle of the 48-bit MAC (between the + company_id and extension identifier portions of the EUI-48 value). + For example, for a globally unique 48-bit EUI-48 identifier of the + form: + + most-significant least-significant + bit bit + |0 1|1 3|3 4| + |0 5|6 1|2 7| + +----------------+----------------+----------------+ + |cccccc0gcccccccc|cccccccceeeeeeee|eeeeeeeeeeeeeeee| + +----------------+----------------+----------------+ + + where "c" are the bits of the assigned company_id, "0" is the + value of the universal/local bit to indicate global scope, "g" is + the group/individual bit, and "e" are the bits of the extension + identifier, the IPv6 interface identifier would be of the form: + + most-significant least-significant + bit bit + |0 1|1 3|3 4|4 6| + |0 5|6 1|2 7|8 3| + +----------------+----------------+----------------+----------------+ + + |cccccc1gcccccccc|cccccccc11111111|11111110eeeeeeee|eeeeeeeeeeeeeeee| + +----------------+----------------+----------------+----------------+ + + 2) If an IEEE global identifier is not available, a different source + of uniqueness should be used. Suggested sources of uniqueness + include link-layer addresses, machine serial numbers, et cetera. + + + +Varada, et al. Standards Track [Page 6] + +RFC 5072 IP Version 6 over PPP September 2007 + + + In this case, the "u" bit of the interface identifier MUST be set + to zero (0). + + 3) If a good source of uniqueness cannot be found, it is recommended + that a random number be generated. In this case, the "u" bit of + the interface identifier MUST be set to zero (0). + + Good sources [1] of uniqueness or randomness are required for the + interface identifier negotiation to succeed. If neither a unique + number nor a random number can be generated, it is recommended that a + zero value be used for the interface identifier transmitted in the + Configure-Request. In this case, the PPP peer may provide a valid + non-zero interface identifier in its response as described below. + Note that if at least one of the PPP peers is able to generate + separate non-zero numbers for itself and its peer, the identifier + negotiation will succeed. + + When a Configure-Request is received with the Interface-Identifier + Configuration Option and the receiving peer implements this option, + the received interface identifier is compared with the interface + identifier of the last Configure-Request sent to the peer. Depending + on the result of the comparison, an implementation MUST respond in + one of the following ways: + + If the two interface identifiers are different but the received + interface identifier is zero, a Configure-Nak is sent with a non-zero + interface-identifier value suggested for use by the remote peer. + Such a suggested interface identifier MUST be different from the + interface identifier of the last Configure-Request sent to the peer. + It is recommended that the value suggested be consistently + reproducible across initializations of the IPV6CP finite state + machine (administrative Close and reOpen, reboots, etc). The "u" + (universal/local) bit of the suggested identifier MUST be set to zero + (0) regardless of its source unless the globally unique EUI-48/EUI-64 + derived identifier is provided for the exclusive use by the remote + peer. + + If the two interface identifiers are different and the received + interface identifier is not zero, the interface identifier MUST be + acknowledged, i.e., a Configure-Ack is sent with the requested + interface identifier, meaning that the responding peer agrees with + the interface identifier requested. + + If the two interface identifiers are equal and are not zero, + Configure-Nak MUST be sent specifying a different non-zero + interface-identifier value suggested for use by the remote peer. It + is recommended that the value suggested be consistently reproducible + across initializations of the IPV6CP finite state machine + + + +Varada, et al. Standards Track [Page 7] + +RFC 5072 IP Version 6 over PPP September 2007 + + + (administrative Close and reOpen, reboots, etc). The "u" + (universal/local) bit of the suggested identifier MUST be set to zero + (0) regardless of its source unless the globally unique EUI-48/EUI-64 + derived identifier is provided for the exclusive use by the remote + peer. + + If the two interface identifiers are equal to zero, the interface + identifier's negotiation MUST be terminated by transmitting the + Configure-Reject with the interface-identifier value set to zero. In + this case, a unique interface identifier cannot be negotiated. + + If a Configure-Request is received with the Interface-Identifier + Configuration Option and the receiving peer does not implement this + option, Configure-Reject is sent. + + A new Configure-Request SHOULD NOT be sent to the peer until normal + processing would cause it to be sent (that is, until a Configure-Nak + is received or the Restart timer runs out [1]). + + A new Configure-Request MUST NOT contain the interface-identifier + option if a valid Interface-Identifier Configure-Reject is received. + + Reception of a Configure-Nak with a suggested interface identifier + different from that of the last Configure-Nak sent to the peer + indicates a unique interface identifier. In this case, a new + Configure-Request MUST be sent with the identifier value suggested in + the last Configure-Nak from the peer. But if the received interface + identifier is equal to the one sent in the last Configure-Nak, a new + interface identifier MUST be chosen. In this case, a new Configure- + Request SHOULD be sent with the new tentative interface identifier. + This sequence (transmit Configure-Request, receive Configure-Request, + transmit Configure-Nak, receive Configure-Nak) might occur a few + times, but it is extremely unlikely to occur repeatedly. More + likely, the interface identifiers chosen at either end will quickly + diverge, terminating the sequence. + + If negotiation of the interface identifier is required, and the peer + did not provide the option in its Configure-Request, the option + SHOULD be appended to a Configure-Nak. The tentative value of the + interface identifier given must be acceptable as the remote interface + identifier; i.e., it should be different from the identifier value + selected for the local end of the PPP link. The next Configure- + Request from the peer may include this option. If the next + Configure-Request does not include this option, the peer MUST NOT + send another Configure-Nak with this option included. It should + assume that the peer's implementation does not support this option. + + + + + +Varada, et al. Standards Track [Page 8] + +RFC 5072 IP Version 6 over PPP September 2007 + + + By default, an implementation SHOULD attempt to negotiate the + interface identifier for its end of the PPP connection. + + A summary of the Interface-Identifier Configuration Option format is + shown below. The fields are transmitted from left to right. + + 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 | Interface-Identifier (MS Bytes) + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + Interface-Identifier (cont) + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + Interface-Identifier (LS Bytes) | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Type + + 1 + + Length + + 10 + + Interface-Identifier + + The 64-bit interface identifier, which is very likely to be + unique on the link, or zero if a good source of uniqueness + cannot be found. + + Default + + If no valid interface identifier can be successfully + negotiated, no default interface-identifier value should be + assumed. The procedures for recovering from such a case are + unspecified. One approach is to manually configure the + interface identifier of the interface. + +5. Stateless Autoconfiguration and Link-Local Addresses + + The interface identifier of IPv6 unicast addresses [5] of a PPP + interface SHOULD be negotiated in the IPV6CP phase of the PPP + connection setup (see Section 4.1). If no valid interface identifier + has been successfully negotiated, procedures for recovering from such + a case are unspecified. One approach is to manually configure the + interface identifier of the interface. + + + + + +Varada, et al. Standards Track [Page 9] + +RFC 5072 IP Version 6 over PPP September 2007 + + + The negotiated interface identifier is used by the local end of the + PPP link to autoconfigure an IPv6 link-local unicast address for the + PPP interface. However, it SHOULD NOT be assumed that the same + interface identifier is used in configuring global unicast addresses + for the PPP interface using IPv6 stateless address autoconfiguration + [3]. The PPP peer MAY generate one or more interface identifiers, + for instance, using a method described in [8], to autoconfigure one + or more global unicast addresses. + + As long as the interface identifier is negotiated in the IPV6CP phase + of the PPP connection setup, it is redundant to perform duplicate + address detection (DAD) as a part of the IPv6 Stateless Address + Autoconfiguration protocol [3] on the IPv6 link-local address + generated by the PPP peer. It may also be redundant to perform DAD + on any global unicast addresses configured (using an interface + identifier that is either negotiated during IPV6CP or generated, for + instance, as per [8]) for the interface as part of the IPv6 Stateless + Address Autoconfiguration protocol [3] provided that the following + two conditions are met: + + 1) The prefixes advertised through the Router Advertisement + messages by the access router terminating the PPP link are + exclusive to the PPP link. + + 2) The access router terminating the PPP link does not + autoconfigure any IPv6 global unicast addresses from the + prefixes that it advertises. + + Therefore, it is RECOMMENDED that for PPP links with the IPV6CP + interface-identifier option enabled and satisfying the aforementioned + two conditions, the default value of the DupAddrDetectTransmits + autoconfiguration variable [3] is set to zero by the system + management. 3GPP2 networks are an example of a technology that uses + PPP to enable a host to obtain an IPv6 global unicast address and + satisfies the aforementioned two conditions [10]. 3GPP networks are + another example ([11] [13]). + + Link-local addresses + + Link-local addresses of PPP interfaces have the following format: + + | 10 bits | 54 bits | 64 bits | + +----------+------------------------+-----------------------------+ + |1111111010| 0 | Interface-Identifier | + +----------+------------------------+-----------------------------+ + + + + + + +Varada, et al. Standards Track [Page 10] + +RFC 5072 IP Version 6 over PPP September 2007 + + + The most significant 10 bits of the address is the Link-Local prefix + FE80::. 54 zero bits pad out the address between the Link-Local + prefix and the interface-identifier fields. + +6. Security Considerations + + Lack of link security, such as authentication, trigger the security + concerns raised in [3] when the stateless address autoconfiguration + method is employed for the generation of global unicast IPv6 + addresses out of interface identifiers that are either negotiated + through the IPV6CP or generated, for instance, using a method + described in [8]. Thus, the mechanisms that are appropriate for + ensuring PPP link security are addressed below, together with the + reference to a generic threat model. + + The mechanisms that are appropriate for ensuring PPP link Security + are: 1) Access Control Lists that apply filters on traffic received + over the link for enforcing admission policy, 2) an Authentication + protocol that facilitates negotiations between peers [15] to select + an authentication method (e.g., MD5 [16]) for validation of the peer, + and 3) an Encryption protocol that facilitates negotiations between + peers to select encryption algorithms (or crypto-suites) to ensure + data confidentiality [17]. + + There are certain threats associated with peer interactions on a PPP + link even with one or more of the above security measures in place. + For instance, using the MD5 authentication method [16] exposes one to + replay attack, where an attacker could intercept and replay a + station's identity and password hash to get access to a network. The + user of this specification is advised to refer to [15], which + presents a generic threat model, for an understanding of the threats + posed to the security of a link. The reference [15] also gives a + framework to specify requirements for the selection of an + authentication method for a given application. + +7. IANA Considerations + + The IANA has assigned value 1 for the Type field of the IPv6 datagram + interface-identifier option specified in this document. The current + assignment is up-to-date at [9]. + +8. Acknowledgments + + This document borrows from the Magic-Number LCP option and as such is + partially based on previous work done by the PPP working group. + + The editor is grateful for the input provided by members of the IPv6 + community in the spirit of updating RFC 2472. Thanks, in particular, + + + +Varada, et al. Standards Track [Page 11] + +RFC 5072 IP Version 6 over PPP September 2007 + + + go to Pete Barany and Karim El Malki for their technical + contributions. Also, thanks to Alex Conta for a thorough review, + Stephen Kent for helping with security aspects, and Spencer Dawkins + and Pekka Savola for the nits. Finally, the author is grateful to + Jari Arkko for his initiation to bring closure to this specification. + +9. References + +9.1. Normative References + + [1] Simpson, W., Ed., "The Point-to-Point Protocol (PPP)", STD 51, + RFC 1661, July 1994. + + [2] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) + Specification", RFC 2460, December 1998. + + [3] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless Address + Autoconfiguration", RFC 4862, September 2007. + + [4] IEEE, "Guidelines For 64-bit Global Identifier (EUI-64)", + http://standards.ieee.org/regauth/oui/tutorials/EUI64.html + + [5] Hinden, R. and S. Deering, "IP Version 6 Addressing + Architecture", RFC 4291, February 2006. + + [6] Bradner, S., "Key words for use in RFCs to Indicate Requirement + Levels", BCP 14, RFC 2119, March 1997. + + [7] Haskin, D. and E. Allen, "IP Version 6 over PPP", RFC 2472, + December 1998. + + [8] Narten T., Draves, R., and S. Krishnan, "Privacy Extensions for + Stateless Address Autoconfiguration in IPv6", RFC 4941, + September 2007. + +9.2. Informative references + + [9] IANA, "Assigned Numbers," http://www.iana.org/numbers.html + + [10] 3GPP2 X.S0011-002-C v1.0, "cdma2000 Wireless IP Network + Standard: Simple IP and Mobile IP Access Services," September + 2003. + + [11] 3GPP TS 29.061 V6.4.0, "Interworking between the Public Land + Mobile Network (PLMN) Supporting packet based services and + Packet Data Networks (PDN) (Release 6)," April 2005. + + + + + +Varada, et al. Standards Track [Page 12] + +RFC 5072 IP Version 6 over PPP September 2007 + + + [12] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, C., + and M. Carney, "Dynamic Host Configuration Protocol for IPv6 + (DHCPv6)", RFC 3315, July 2003. + + [13] 3GPP TS 23.060 v6.8.0, "General Packet Radio Service (GPRS); + Service description; Stage 2 (Release 6)," March 2005. + + [14] Narten, T. and C. Burton, "A Caution On The Canonical Ordering + Of Link-Layer Addresses", RFC 2469, December 1998. + + [15] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J., and H. + Levkowetz, Ed., "Extensible Authentication Protocol (EAP)", RFC + 3748, June 2004. + + [16] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, April + 1992. + + [17] Meyer, G., "The PPP Encryption Control Protocol (ECP)", RFC + 1968, June 1996. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Varada, et al. Standards Track [Page 13] + +RFC 5072 IP Version 6 over PPP September 2007 + + +Appendix A: Global Scope Addresses + + A node on the PPP link creates global unicast addresses either + through stateless or stateful address autoconfiguration mechanisms. + In the stateless address autoconfiguration [3], the node relies on + sub-net prefixes advertised by the router via the Router + Advertisement messages to obtain global unicast addresses from an + interface identifier. In the stateful address autoconfiguration, the + host relies on a Stateful Server, like DHCPv6 [12], to obtain global + unicast addresses. + +Appendix B: Changes from RFC 2472 + + The following changes were made from RFC 2472 "IPv6 over PPP": + + - Minor updates to Sections 3 and 4 + + - Updated the text in Section 4.1 to include the reference to + Appendix A and minor text clarifications. + + - Removed Section 4.2 on IPv6-Compression-Protocol based on IESG + recommendation, and created a new standards-track document to + cover negotiation of the IPv6 datagram compression protocol using + IPV6CP. + + - Updated the text in Section 5 to: (a) allow the use of one or more + interface identifiers generated by a peer, in addition to the use + of interface identifier negotiated between peers of the link, in + the creation of global unicast addresses for the local PPP + interface, and (b) identify cases against the DAD of created non- + link-local addresses. + + - Added new and updated references. + + - Added Appendix A + + + + + + + + + + + + + + + + +Varada, et al. Standards Track [Page 14] + +RFC 5072 IP Version 6 over PPP September 2007 + + +Authors' Addresses + + Dimitry Haskin + Ed Allen + + Srihari Varada (Editor) + TranSwitch Corporation + 3 Enterprise Dr. + Shelton, CT 06484. US. + + Phone: +1 203 929 8810 + EMail: varada@ieee.org + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Varada, et al. Standards Track [Page 15] + +RFC 5072 IP Version 6 over PPP September 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. + + 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. + + + + + + + + + + + + +Varada, et al. Standards Track [Page 16] + -- cgit v1.2.3