Network Working Group S. Krishnan Internet-Draft Ericsson Updates: 4861 (if approved) G. Daley Intended status: Standards Track NetStar Networks Expires: May 7, 2009 November 3, 2008 Simple procedures for Detecting Network Attachment in IPv6 draft-ietf-dna-simple-05 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 May 7, 2009. Abstract Detecting Network Attachment allows hosts to assess if its existing addressing or routing configuration is valid for a newly connected network. This document provides simple procedures for detecting network attachment in IPv6 hosts, and procedures for routers to support such services. Krishnan & Daley Expires May 7, 2009 [Page 1]
Internet-Draft Simple DNA November 2008 Table of Contents 1. Requirements notation . . . . . . . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. Goals . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Applicability . . . . . . . . . . . . . . . . . . . . . . 3 2.3. Link Identification model . . . . . . . . . . . . . . . . 4 2.4. DNA Roles . . . . . . . . . . . . . . . . . . . . . . . . 4 2.5. Working Assumptions . . . . . . . . . . . . . . . . . . . 4 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Host Operations . . . . . . . . . . . . . . . . . . . . . . . 5 4.1. Host data structures . . . . . . . . . . . . . . . . . . . 6 4.2. Steps involved in detecting link change . . . . . . . . . 6 4.3. Link-Layer Indication . . . . . . . . . . . . . . . . . . 6 4.4. Sending Neighbor Discovery probes . . . . . . . . . . . . 6 4.5. Contents of the Neighbor Discovery messages . . . . . . . 8 4.5.1. Neighbor Solicitation messages . . . . . . . . . . . . 8 4.5.2. Router Solicitation messages . . . . . . . . . . . . . 8 4.6. Sending DHCPv6 probes . . . . . . . . . . . . . . . . . . 8 4.7. Response Gathering . . . . . . . . . . . . . . . . . . . . 9 4.8. Further Host Operations . . . . . . . . . . . . . . . . . 10 4.9. Recommended retransmission behavior . . . . . . . . . . . 10 5. Router Operations . . . . . . . . . . . . . . . . . . . . . . 11 5.1. DHCPv6 Router/Server Operations . . . . . . . . . . . . . 12 6. Pseudocode for Simple DNA . . . . . . . . . . . . . . . . . . 12 7. Constants . . . . . . . . . . . . . . . . . . . . . . . . . . 14 8. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . 14 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 10. Security Considerations . . . . . . . . . . . . . . . . . . . 15 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 12.1. Normative References . . . . . . . . . . . . . . . . . . . 16 12.2. Informative References . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17 Intellectual Property and Copyright Statements . . . . . . . . . . 18 Krishnan & Daley Expires May 7, 2009 [Page 2]
Internet-Draft Simple DNA November 2008 1. Requirements notation 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]. 2. Introduction Hosts require procedures to simply and reliably identify if they have moved to a different IP network to the one which they have been recently connected. In order to detect change, router and neighbour discovery messages are used to collect reachability and configuration information. This information is used to detect whether the existing router and address prefixes are likely to be present. This document incorporates feedback from host and router operating systems implementors, which seeks to make implementation and adoption of IPv6 change detection procedures simple for general use. 2.1. Goals The goal of this document is to specify a simple procedure for detecting network attachment (Simple DNA) that has the following characteristics. o Routers do not have to be modified to support this scheme. o Handle only the simplest and most likely use cases. o Work at least as quickly as standard neighbor discovery. o False positives are not acceptable. A host should not conclude that there is no link change when there is one. o False negatives are acceptable. A host can conclude that there is a link change when there is none. 2.2. Applicability The Simple DNA protocol provides substantial benefits in some scenarios and does not provide any benefit at all in certain other scenarios. This is intentional as Simple DNA was designed for simplicity rather than completeness. In particular, the Simple DNA protocol provides maximum benefits when a host moves between a small set of known links. When a host moves to a completely new link that is previously unknown, the performance of the Simple DNA protocol will be identical to that using standard neighbor discovery Krishnan & Daley Expires May 7, 2009 [Page 3]
Internet-Draft Simple DNA November 2008 procedures [RFC4861]. 2.3. Link Identification model Earlier methods of detecting network attachment, e.g. the procedure defined in [I-D.ietf-dna-protocol], relied on detecting whether the host was still connected to the same link. If the host was attached to the same link, all information related to the link such as the routers, prefixes and configuration parameters was considered to be valid. The Simple DNA protocol follows an alternate approach where it relies on probing each previously known router to determine whether to use information learnt from THAT router. This allows simple DNA to probe routers learnt from multiple earlier attachments to optimize movement between a known set of links. 2.4. DNA Roles Detecting Network Attachment is performed by hosts by sending IPv6 neighbour discovery and router discovery messages to routers after connecting to a network. It is desirable that routers adopt procedures which allow for fast unicast Router Advertisement (RA) messages. Routers that follow the standard neighbor discovery procedure described in [RFC4861] will delay the router advertisement by a random period between 0 and MAX_RA_DELAY_TIME (defined to be 500ms) as described in Section 6.2.6 of [RFC4861]. This delay can be significant and may result in service disruption. Please note that support for fast unicast RAs is not necessary since the simple dna procedure can continue to work using the NS/NA exchange, which will complete earlier than the RA arrives. The host detects that the link-layer may have changed, and then simultaneously probes the network with Router Solicitations (RSs) and Neighbour Solicitations (NSs). The host uses advertisements to determine if the routers it currently has configured are still available. Additionally, on links with no statelessly configured addresses, the host may make use of DHCPv6 procedures to identify an operable address. 2.5. Working Assumptions There are a series of assumptions about the network environment which underpin these procedures. Krishnan & Daley Expires May 7, 2009 [Page 4]
Internet-Draft Simple DNA November 2008 o The combination of the link layer address and the link local IPv6 address of a router is unique across links. o Hosts receive indications when a link-layer comes up. Without this, they would not know when to commence the DNA procedure. If these assumptions do not hold, host change detection systems will not function optimally. In that case, they may occasionally detect change spuriously, or experience some delay in detecting network attachment. The delays so experienced will be no longer than those caused by following the standard neighbor discovery procedure described in [RFC4861]. If systems do not meet these assumptions or if systems seek deterministic change detection operations they are directed to follow the complete dna procedure as defined in [I-D.ietf-dna-protocol]. 3. Terminology +---------------------+---------------------------------------------+ | Term | Definition | +---------------------+---------------------------------------------+ | Valid IPv6 address | An IPv6 address configured on the node that | | | has a valid lifetime greater than zero. | | | | | Operable IPv6 | An IPv6 address configured on the node that | | address | can be used safely on the current link. | +---------------------+---------------------------------------------+ Table 1: Simple DNA Terminology 4. Host Operations When a host has an existing configuration for IP address prefixes and next hop routing, it may be disconnected from its link-layer, and then subsequently reconnect the link-layer on the same interface. When the link-layer becomes available again, it is important to determine whether the existing addressing and routing configuration are still valid. In order to determine this, the host performs the detecting network attachment procedure. Krishnan & Daley Expires May 7, 2009 [Page 5]
Internet-Draft Simple DNA November 2008 4.1. Host data structures In order to correctly perform the procedure described in this document the host needs to maintain a data structure called the Simple DNA address table (SDAT). This data structure is maintained by the host on a per interface basis. Each entry in the SDAT table consists of at least the following parameters. o IPv6 address and its related parameters like valid lifetime. o Prefix from which the address was formed. o Link-local IPv6 address of the router that advertised the prefix. o Link layer (MAC) address of the router that advertised the prefix. o DHCP Unique IDentifier (DUID) in case DHCPv6 was used to acquire the address [RFC3315]. 4.2. Steps involved in detecting link change The steps involved in basic detection of network attachment are: o Link-Layer Indication o Sending of neighbour discovery or DHCPv6 probes o Response gathering and assessment These steps are described below. 4.3. Link-Layer Indication In order to start Detection of network attachment procedures, a host typically requires a link-layer indication that the medium has become available [RFC4957]. After the indication is received, the host considers all currently configured (non-tentative) IP addresses to as deprecated until the change detection process completes. It SHOULD also set all Neighbor Cache entries for the routers on its Default Router List to STALE. This is done to speed up the acquisition of a new default router when link change has occurred. 4.4. Sending Neighbor Discovery probes When a host receives a link-layer "up" indication, it SHOULD immediately send both a Router Solicitation and if it retains at Krishnan & Daley Expires May 7, 2009 [Page 6]
Internet-Draft Simple DNA November 2008 least one valid IPv6 address, one or more unicast Neighbor Solicitations. The Router Solicitation is sent to the All-routers multicast address using a link-local address as the source address [RFC4861]. Even if the host is in possession of more than one valid IPv6 address, it MUST send only one router solicitation using a valid link-local address as the source address. For the purpose of sending neighbor solicitations to previous routers, the host first needs to pick a subset of operable IPv6 addresses (candidate set) that it wishes to use. How this subset of addresses is picked is based on host configuration. e.g. The host may select configured addresses from each of zero, one or two previously connected links. If the addresses obtained from a previous router are no longer valid, the host does not include these addresses in the candidate set for NS based probing. For each of the addresses in the candidate set, the host looks up the SDAT to find out the link-local and MAC addresses of the router that advertised the prefix used to form the address. It then sends an unicast Neighbor Solicitations to each router's link-local address it obtained from the lookup on the SDAT. The host SHOULD NOT send unicast Neighbor Solicitations to a test node corresponding to an IPv6 address that is no longer valid. Please note that the Neighbour Solicitations SHOULD be sent in parallel with the Router Solicitations. Since sending NSs is just an optimization, doing the NSs and RSs in parallel ensures that the procedure does not run slower than it would if it only used an RS. Be aware that each unicast solicitation which is not successful may cause packet flooding in bridged networks, if the networks are not properly configured. This is further described in Section 8. Where flooding may cause performance issues within the LAN, host SHOULD limit the number of unicast solicitations. Krishnan & Daley Expires May 7, 2009 [Page 7]
Internet-Draft Simple DNA November 2008 4.5. Contents of the Neighbor Discovery messages 4.5.1. Neighbor Solicitation messages This section describes the contents of the neighbor solicitation probe messages sent during the probing procedure. Source Address: A link-local address assigned to the probing host. Destination Address: The link-local address of the router being probed as learnt from the SDAT. Hop Limit: 255 ND Options: Target Address: The link-local address of the router being probed as learnt from the SDAT. The probing node SHOULD NOT include a Source link-layer address option if it has not performed duplicate address detection [RFC4862], for the source address of the NS, on the newly attached link. 4.5.2. Router Solicitation messages This section describes the contents of the router solicitation probe message sent during the probing procedure. Source Address: A link-local address assigned to the probing host. Destination Address: The all-routers multicast address. Hop Limit: 255 The probing node SHOULD NOT include a Source link-layer address option if it has not performed duplicate address detection [RFC4862], for the source address of the NS, on the newly attached link. 4.6. Sending DHCPv6 probes Where the host has acquired addresses from DHCPv6 or the host does not have a global prefix, it MAY prefer to use DHCPv6 messages either before or simultanously with Neighbour Discovery probing. In that case, when the host receives a link-layer indication, it sends a DHCPv6 SOLICIT to All_DHCP_Relay_Agents_and_Servers. This Krishnan & Daley Expires May 7, 2009 [Page 8]
Internet-Draft Simple DNA November 2008 message contains an Identity Addociation for either a Temporary Address (IA_TA) or Non-Temporary Address (IA_NA) [RFC3315]. Where an existing valid address is being tested for operability, this address should be placed in the Identity Association's IAADDR element, and the DUID associated with that address should be copied to the DHCP SOLICIT from the SDAT. In order to quickly acquire a new address in the case that link change has occurred, this SOLICIT message MAY contain the Rapid- Commit option. Where the Rapid-Commit option has not been used, a present DHCP server will respond with an ADVERTISE message. The IP address contained in the Identity Association (IA_TA or IA_NA) will contain an IP Address which is operable for the link. Where Rapid-Commit option has been sent, a DHCPv6 server will respond with REPLY. In addition to being operable, this address is allocated to the host for the lease duration indicated in the Identity Association. 4.7. Response Gathering When a responding Neighbour Advertisement is received from a test node, the host MUST verify that both the IPv6 and link layer (MAC) addresses of the test node match the expected values before utilizing the configuration associated with the detected network (prefixes, MTU etc.). On reception of a Router Advertisement or advertising DHCPv6 message (a REPLY or ADVERTISE) which contains prefixes that intersect with those previously advertised by a known router, the host utilizes the configuration associated with the detected network. When the host receives an advertisement containing only prefixes which are disjoint from known advertised prefixes, the host MUST determine whether the solicited advertisement corresponds to any of the routers probed via NS. If it does, then the host SHOULD conclude that the IPv6 addresses corresponding to that router are no longer valid. Since any NS probes to that router will no longer provide useful information, further probing of that router SHOULD be aborted. Where the conclusions obtained from the Neighbor Solicitation/ Advertisement from a given router and the RS/RA exchange with the same router differ, the results obtained from the RS/RA will be considered definitive. When the host receives a Router Advertisement in reply to the Router Krishnan & Daley Expires May 7, 2009 [Page 9]
Internet-Draft Simple DNA November 2008 Solicitation it sent, the host SHOULD look for a Neighbor Cache entry for the sending router and SHOULD mark that router's Neighbor Cache Entry as REACHABLE if one was found. The host SHOULD add a new Neighbor Cache Entry in the REACHABLE state for the sending router if one does not currently exist. 4.8. Further Host Operations Operations subsequent to detecting network attachment depend upon whether change was detected. After confirming the reachability of the associated router using an NS/NA pair, the host performs the following steps. o The host SHOULD rejoin any solicited nodes' multicast groups for addresses it continues to use. o The host SHOULD select a default router as described in [RFC4861]. If the host has determined that there has been no link change, it SHOULD NOT perform duplicate address detection on the addresses that have been confirmed to be operable. If the NS based probe with a router did not complete or if the RS based probe on the same router completed with different prefixes than the ones in the SDAT the host MUST unconfigure all the existing addresses received from the given router, and MUST begin address configuration techniques, as indicated in the received Router Advertisement [RFC4861][RFC4862]. 4.9. Recommended retransmission behavior In situations where Neighbor Solicitation probes and Router Solicitation probes are used on the same link, it is possible that the NS probe will complete successfully, and then the RS probe will complete later with a different result. If this happens, the implementation SHOULD abandon the results obtained from the NS probe of the router that responded to the RS and the implementation SHOULD behave as if the NS probe did not successfully complete. If the confirmed address was assigned manually, the implementation SHOULD NOT unconfigure the manually assigned address and SHOULD log an error about the mismatching prefix. Where the NS probe does not complete successfully, it usually implies that the host is not attached to the network whose configuration is being tested. In such circumstances, there is typically little value in aggressively retransmitting unicast neighbor solicitations that do not elicit a response. Krishnan & Daley Expires May 7, 2009 [Page 10]
Internet-Draft Simple DNA November 2008 Where unicast Neighbor Solicitations and Router Solicitations are sent in parallel, one strategy is to forsake retransmission of Neighbor Solicitations and to allow retransmission only of Router Solicitations or DHCPv6. In order to reduce competition between unicast Neighbor Solicitations and Router Solicitations and DHCPv6 retransmissions, a DNAv6 implementation that retransmits may utilize the retransmission strategy described in the DHCPv6 specification [RFC3315], scheduling DNAv6 retransmissions between Router Solicitation or DHCPv6 retransmissions. If a response is received to any unicast Neighbor Solicitation, Router Solicitation or DHCPv6 message, pending retransmissions MUST be canceled [RFC3315][RFC3736]. A Simple DNA implementation SHOULD NOT retransmit a Neighbor Solicitation more than twice. To provide damping in the case of spurious Link Up indications, the host SHOULD NOT perform the Simple DNA procedure more than once a second. 5. Router Operations Hosts checking their network attachment are unsure of their address status, and may be using Tentative link-layer addressing information in their router or neighbour solicitations. A router which desires to support hosts' DNA operations MUST process Tentative Options from unicast source addressed Router and Neighbour Solicitations, as described in [I-D.ietf-dna-tentative]. Krishnan & Daley Expires May 7, 2009 [Page 11]
Internet-Draft Simple DNA November 2008 5.1. DHCPv6 Router/Server Operations DHCPv6 Server operations occur in accordance with the DHCPv6 RFC [RFC3315]. 6. Pseudocode for Simple DNA /* Link up indication received on INTERFACE */ /* Start Simple DNA process */ /* Mark All Addresses as deprecated */ Configured_Address_List=Get_Address_List(INTERFACE); foreach Configured_Address in Configured_Address_List { if (Get_Address_State(Configured_Address)!=AS_TENTATIVE) { Set_Address_State(Configured_Address,AS_DEPRECATED); } } /* Mark all routers' NC entries as STALE to speed up */ /* acquisition of new router if link change has occurred */ foreach Router_Address in DEFAULT_ROUTER_LIST { NCEntry=Get_Neighbor_Cache_Entry(Router_Address); Set_Neighbor_Cache_Entry_State(NCEntry,NCS_STALE); } /* Thread A : Send Router Solicitation */ RS_Target_Address=FF02::2; RS_Source_Address=Get_Any_Link_Local_Address(INTERFACE); Send_Router_Solicitation(RS_Source_Address,RS_Target_Address); /* Thread B : Send Neighbor Solicitation(s) */ Previously_Known_Router_List=Get_Router_List_from_SDAT(); NS_Source_Address=Get_Any_Link_Local_Address(INTERFACE); foreach Router_Address in Previously_Known_Router_List { if (Get_Any_Valid_Address_from_SDAT(Router_Address)) { Send_Neighbor_Solicitation(NS_Source_Address,Router_Address); } } /* Thread C : Response collection */ Krishnan & Daley Expires May 7, 2009 [Page 12]
Internet-Draft Simple DNA November 2008 /* Received Router Advertisement processing */ /* Only for RAs received as response to DNA RSs */ L3_Source=Get_L3_Source(RECEIVED_MESSAGE); L2_Source=Get_L2_Source(RECEIVED_MESSAGE); SDAT_Entry_List=Get_Entries_from_SDAT_L2L3(L3_Source,L2_Source)); foreach SDAT_Entry in SDAT_Entry_List { if (Exists_PIO(RECEIVED_MESSAGE,Get_Prefix(SDAT_Entry))) { /* Address is operable. Configure on Interface */ /* Rejoin solicited-node multicast group for address */ } else { /* If address is configured on interface, remove it */ /* This could be because of a NA arriving before RA */ } } /* Mark router as reachable */ NCEntry=Get_Neighbor_Cache_Entry(L3_Source); if (NCEntry is not NULL) { Set_Neighbor_Cache_Entry_State(NCEntry,NCS_REACHABLE); } else { Create_Neighbor_Cache_Entry(L3_Source,NCS_REACHABLE); } /* Ignore further NAs from this router */ Add_Router_to_NA_Ignore_List(L3_Source); /* Received Neighbor Advertisement processing */ /* Only for NAs received as response to DNA NSs */ L3_Source=Get_L3_Source(RECEIVED_MESSAGE); L2_Source=Get_L2_Source(RECEIVED_MESSAGE); if (Is_Router_on_NA_Ignore_List(L3_Source)) { /* Ignore message and wait for next message */ continue; } SDAT_Entry_List=Get_Entries_from_SDAT_L2L3(L3_Source,L2_Source)); Krishnan & Daley Expires May 7, 2009 [Page 13]
Internet-Draft Simple DNA November 2008 foreach SDAT_Entry in SDAT_Entry_List { /* Address is operable. Configure on Interface */ } Figure 1: Pseudocode for Simple DNA 7. Constants These constants are described as in [I-D.ietf-dna-protocol]. UNICAST_RA_INTERVAL Definition: The interval corresponding to the maximum average rate of Router Solicitations that the router is prepared to service with unicast responses. This is the interval at which the token bucket controlling the unicast responses is replenished. Value: 50 milliseconds MAX_UNICAST_RA_BURST Definition: The maximum size burst of Router Solicitations that the router is prepared to service with unicast responses. This is the maximum number of tokens allowed in the token bucket controlling the unicast responses. Value: 20 SEND_NA_GRACE_TIME Definition: An optional period to wait after Neighbour Solicitation before adopting a non-SEND RA's link change information. Value: 40 milliseconds 8. Open Issues This section documents issues that are still outstanding within the document, and the simple DNA solution in general. Rate limitation for solicitations. Krishnan & Daley Expires May 7, 2009 [Page 14]
Internet-Draft Simple DNA November 2008 Hosts MAY implement hysteresis mechanisms to pace solicitations where necessary to prevent damage to a particular medium. Implementors should be aware that when such hysteresis is triggered, Detecting Network Attachment may be slowed, which may affect application traffic. 9. IANA Considerations There are no changes to IANA registries required in this document. 10. Security Considerations When providing fast responses to router solicitations, it is possible to cause collisions with other signaling packets on contention based media. This can cause repeated packet loss or delay when multiple routers are present on the link. As such the fast router advertisement system is NOT RECOMMENDED in this form for media which are susceptible to collision loss. Such environments may be better served using the procedures defined in [I-D.ietf-dna-protocol]. A host may receive Router Advertisements from non SEND devices, after receiving a link-layer indications. While it is necessary to assess quickly whether a host has moved to another network, it is important that the host's current secured SEND [RFC3971] router information is not replaced by an attacker which spoofs an RA and purports to change the link. As such, the host SHOULD send a Neighbour Solicitation to the existing SEND router upon link-up indication as described above in Section 4.3. The host SHOULD then ensure that unsecured router information does not cause deletion of existing SEND state, within MIN_DELAY_BETWEEN_RAS, in order to allow for a present SEND router to respond. The host MAY delay SEND_NA_GRACE_TIME after transmission before adopting a new default router, if it is operating on a network where there is significant threat of RA spoofing. Even if SEND signatures on RAs are used, it may not be immediately clear if the router is authorized to make such advertisements. As such, a host SHOULD NOT treat such devices as secure until and unless authorization delegation discovery is successful. It is easy for hosts soliciting without SEND to deplete a SEND Krishnan & Daley Expires May 7, 2009 [Page 15]
Internet-Draft Simple DNA November 2008 router's fast advertisement token buckets, and consume additional bandwidth. As such, a router MAY choose to preserve a portion of their token bucket to serve solicitations with SEND signatures. 11. Acknowledgments This document is the product of a discussion between the authors had with Bernard Aboba, Thomas Narten, Erik Nordmark and Dave Thaler at IETF 69. The authors would like to thank them for clearly detailing the requirements of the solution and the goals it needed to meet and for helping to explore the solution space. The authors would like to thank the authors and editors of the complete DNA specification for detailing the overall problem space and solutions. The authors would like to thank Jari Arkko for driving the evolution of a simple and probabilistic DNA solution. The authors would like to thank Bernard Aboba, Thomas Narten, Sathya Narayan, Julien Laganier, Domagoj Premec, Jin Hyeock-Choi, Alfred Hoenes and Frederic Rossi for performing reviews on the document and providing valuable comments to drive the document forward. 12. References 12.1. Normative References [I-D.ietf-dna-tentative] Daley, G., Nordmark, E., and N. Moore, "Tentative Options for IPv6 Neighbour Discovery", draft-ietf-dna-tentative-01 (work in progress), July 2007. [I-D.ietf-dna-protocol] Narayanan, S., "Detecting Network Attachment in IPv6 Networks (DNAv6)", draft-ietf-dna-protocol (work in progress), June 2007. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [RFC3736] Droms, R., "Stateless Dynamic Host Configuration Protocol (DHCP) Service for IPv6", RFC 3736, April 2004. [RFC3971] Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure Neighbor Discovery (SEND)", RFC 3971, March 2005. Krishnan & Daley Expires May 7, 2009 [Page 16]
Internet-Draft Simple DNA November 2008 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, September 2007. 12.2. Informative References [RFC4957] Krishnan, S., Montavont, N., Njedjou, E., Veerepalli, S., and A. Yegin, "Link-Layer Event Notifications for Detecting Network Attachments", RFC 4957, August 2007. [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless Address Autoconfiguration", RFC 4862, September 2007. Authors' Addresses Suresh Krishnan Ericsson 8400 Decarie Blvd. Town of Mount Royal, QC Canada Phone: +1 514 345 7900 x42871 Email: suresh.krishnan@ericsson.com Greg Daley NetStar Networks Level 9/636 St Kilda Rd Melbourne, Victoria 3004 Australia Phone: +61 3 8532 4042 Email: gdaley@netstarnetworks.com Krishnan & Daley Expires May 7, 2009 [Page 17]
Internet-Draft Simple DNA November 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. Krishnan & Daley Expires May 7, 2009 [Page 18]
