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Checking references for intended status: Informational ---------------------------------------------------------------------------- == Unused Reference: 'I-D.ietf-v6ops-rfc3316bis' is defined on line 291, but no explicit reference was found in the text -- Obsolete informational reference (is this intentional?): RFC 1981 (Obsoleted by RFC 8201) -- Obsolete informational reference (is this intentional?): RFC 3633 (Obsoleted by RFC 8415) -- Obsolete informational reference (is this intentional?): RFC 4941 (Obsoleted by RFC 8981) Summary: 0 errors (**), 0 flaws (~~), 8 warnings (==), 4 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 V6OPS Working Group C. Byrne 3 Internet-Draft T-Mobile USA 4 Intended Status: Informational D. Drown 5 Expires: August 2, 2013 January 29, 2013 7 Extending an IPv6 /64 Prefix from a 3GPP Mobile Interface to a LAN 8 draft-ietf-v6ops-64share-01 10 Abstract 12 This document describes three methods for extending an IPv6 /64 13 prefix from a User Equipment 3GPP radio interface to a LAN. 15 Status of this Memo 17 This Internet-Draft is submitted in full conformance with the 18 provisions of BCP 78 and BCP 79. 20 Internet-Drafts are working documents of the Internet Engineering 21 Task Force (IETF). Note that other groups may also distribute 22 working documents as Internet-Drafts. The list of current Internet- 23 Drafts is at http://datatracker.ietf.org/drafts/current/. 25 Internet-Drafts are draft documents valid for a maximum of six months 26 and may be updated, replaced, or obsoleted by other documents at any 27 time. It is inappropriate to use Internet-Drafts as reference 28 material or to cite them other than as "work in progress." 30 This Internet-Draft will expire on August 2, 2013. 32 Copyright and License Notice 34 Copyright (c) 2013 IETF Trust and the persons identified as the 35 document authors. All rights reserved. 37 This document is subject to BCP 78 and the IETF Trust's Legal 38 Provisions Relating to IETF Documents 39 (http://trustee.ietf.org/license-info) in effect on the date of 40 publication of this document. Please review these documents 41 carefully, as they describe your rights and restrictions with respect 42 to this document. Code Components extracted from this document must 43 include Simplified BSD License text as described in Section 4.e of 44 the Trust Legal Provisions and are provided without warranty as 45 described in the Simplified BSD License. 47 V6OPS Working Group draft-ietf-v6ops-64share-01 January 29, 2013 49 Table of Contents 51 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 52 2. The Challenge of Providing IPv6 Addresses to a LAN via a 3GPP 53 UE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 54 3. Methods for Extending the 3GPP Interface /64 IPv6 Prefix to a 55 LAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 56 3.0 General Behavior for All Scenarios . . . . . . . . . . . . . 3 57 3.1 Scenario 1: No Global Address on the UE . . . . . . . . . . 4 58 3.2 Scenario 2: Global Address Only Assigned to LAN . . . . . . 5 59 3.3 Scenario 3: A Single Global Address Assigned to 3GPP Radio 60 and LAN Interface . . . . . . . . . . . . . . . . . . . . . 6 61 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 62 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7 63 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 7 64 7. Informative References . . . . . . . . . . . . . . . . . . . . 7 66 V6OPS Working Group draft-ietf-v6ops-64share-01 January 29, 2013 68 1. Introduction 70 3GPP mobile cellular networks such as GSM, UMTS, and LTE have 71 architectural support for IPv6 [RFC6459], but only 3GPP Release-10 72 and onwards of the 3GPP specification supports DHCPv6 Prefix 73 Delegation [RFC3633] for delegating IPv6 prefixes to a LAN. To 74 facilitate the use of IPv6 in a LAN prior to deployment of DHCPv6 75 Prefix Delegation in 3GPP networks and in User Equipment (UE), this 76 document describes how the 3GPP UE interface assigned global /64 77 prefix may be extended from the 3GPP radio interface to a LAN. This 78 is achieved by receiving the Router Advertisement (RA) [RFC4861] 79 announced globally unique /64 IPv6 prefix from the 3GPP radio 80 interface and then advertise the same IPv6 prefix to the LAN with RA. 82 This document describes three methods for achieving IPv6 prefix 83 extension from a 3GPP radio interface to a LAN including: 1) The 3GPP 84 UE does not have a global scope IPv6 address on any interface, only 85 link-local IPv6 addresses are present on the UE 2) The 3GPP UE only 86 has a global scope address on the LAN interface 3) The 3GPP UE 87 maintains the same consistent 128 bit global scope IPv6 anycast 88 address [RFC4291] on the 3GPP radio interface and the LAN interface. 89 The LAN interface is configured as a /64 and the 3GPP radio interface 90 is configured as a /128. 92 Section 3 describes the characteristics of each of the three 93 approaches. 95 2. The Challenge of Providing IPv6 Addresses to a LAN via a 3GPP UE 97 As described in [RFC6459], 3GPP networks assign a /64 global scope 98 prefix to each UE using RA. DHCPv6 Prefix Delegation is an optional 99 part of 3GPP Release-10 and is not covered by any earlier releases. 100 Neighbor Discovery Proxy (ND Proxy) [RFC4389] functionality has been 101 suggested as an option for extending the assigned /64 from the 3GPP 102 interface to the LAN, but ND Proxy is an experimental protocol and 103 has some limitations with loop-avoidance. 105 DHCPv6 is the best way to delegate a prefix to a LAN. The methods 106 described in this document should only be applied when deploying 107 DHCPv6 Prefix Delegation is not achievable in the 3GPP network and 108 the UE. 110 3. Methods for Extending the 3GPP Interface /64 IPv6 Prefix to a LAN 112 3.0 General Behavior for All Scenarios 114 As [RFC6459] describes, the 3GPP network assigned /64 is completely 115 dedicated to the UE and the gateway does not consume any of the /64 117 V6OPS Working Group draft-ietf-v6ops-64share-01 January 29, 2013 119 addresses. The gateway routes the entire /64 to the UE and does not 120 perform ND or Network Unreachability Detection (NUD) [RFC4861]. 121 Communication between the UE and the gateway is only done using link- 122 local addresses and the link is point-to-point. This allows for the 123 UE to reliably manipulate the /64 from the 3GPP radio interface 124 without negatively impacting the point-to-point 3GPP radio link 125 interface. The LAN interface RA configuration must be tightly 126 coupled with the 3GPP interface state. If the 3GPP interface goes 127 down or changes address, that state should be reflected in the LAN 128 IPv6 configuration. Just as in a standard IPv6 router, the packet 129 TTL will be decremented when passing packets between interfaces 130 across the UE. 132 3.1 Scenario 1: No Global Address on the UE 134 In this case, the UE receives the /64 from the 3GPP network via RA 135 and simply configures Neighbor Discovery Protocol (NDP) [RFC4861] on 136 the LAN interface to announce the /64 via RA. The 3GPP UE does not 137 assign itself any global IPv6 addresses. The UE cannot originate or 138 terminate any global scope packets in this case since it does not 139 have a global scope IPv6 address to source or receive packets. The 140 LAN attached devices have complete access to the /64, but the 3GPP UE 141 only has link-local addresses. 143 This method is appropriate for a use-case where the UE is effectively 144 an IPv6 router that does not require any global connectivity. No 145 global connectivity will prevent proper Path MTU Discovery [RFC1981] 147 Below is the general procedure for this scenario: 149 1. The user activates router functionality for a LAN on the UE. 151 2. The UE checks to make sure the 3GPP interface is active and has 152 an IPv6 address. If the interface does not have an IPv6 address, 153 an attempt will be made to acquire one, or else the procedure 154 will terminate. 156 3. In this example, the UE finds the 3GPP interface has the IPv6 157 address 2001:db8:ac10:f002:1234:4567:0:9/64 assigned and active. 159 4. The UE copies the prefix 2001:db8:ac10:f002::/64 from the 3GPP 160 interface to the LAN interface, removes the global IPv6 address 161 configuration from the 3GPP radio interface, and begins 162 announcing the global prefix 2001:db8:ac10:f002::/64 via RA to 163 the LAN. The 3GPP interface and LAN interface only maintain 164 link-local addresses while the UE uses RA to announce the /64 to 165 the LAN. 167 V6OPS Working Group draft-ietf-v6ops-64share-01 January 29, 2013 169 5. Since the UE and gateway do not assign any of the addresses from 170 the /64, there is no chance of an address conflict on the 3GPP 171 radio interface. On the LAN interface, there is no chance of an 172 address conflict since the hosts on the LAN will use Duplicate 173 Address Detection (DAD) [RFC4862]. 175 3.2 Scenario 2: Global Address Only Assigned to LAN 177 For this case, the UE receives the RA from the 3GPP network but does 178 not use a global address on the 3GPP interface. The 3GPP RA /64 179 prefix information is used to configure NDP on the LAN and assigns 180 itself an address on the LAN link. The LAN interface use RA to 181 announces the prefix to the LAN. The UE LAN interface defends its 182 LAN IPv6 address with DAD. 184 This method allows the UE to originate and terminate IPv6 185 communications as a host while acting as an IPv6 router. The 186 movement of the IPv6 prefix from the 3GPP radio interface to the LAN 187 interface may result in long-lived data connections being terminated 188 during the transition from a host-only mode to router-and-host mode. 189 This method is appropriate if the UE or software on the UE cannot 190 support multiple interfaces with the same anycast IPv6 address and 191 the UE requires global connectivity while acting as a router. 193 Below is the general procedure for this scenario: 195 1. The user activates router functionality for a LAN on the UE. 197 2. The UE checks to make sure the 3GPP interfaces is active and has 198 an IPv6 address. If the interface does not have an IPv6 address, 199 an attempt will be made to acquire one, or else the procedure 200 will terminate. 202 3. In this example, the UE finds the 3GPP interface has the IPv6 203 address 2001:db8:ac10:f002:1234:4567:0:9 assigned and active. 205 4. The UE moves the address 2001:db8:ac10:f002:1234:4567:0:9 as a 206 /64 from the 3GPP interfaces to the LAN interface and begins 207 announcing the prefix 2001:db8:ac10:f002::/64 via RA to the LAN. 208 For this example, the LAN has 2001:db8:ac10:f002:1234:4567:0:9/64 209 and the 3GPP radio only has a link-local address. 211 5. The UE directly processes all packets destine to itself at 212 2001:db8:ac10:f002:1234:4567:0:9. 214 6. The UE, acting as a router running NDP on the LAN, will route 216 V6OPS Working Group draft-ietf-v6ops-64share-01 January 29, 2013 218 packet to and from the LAN. IPv6 packets passing between 219 interfaces will have the TTL decremented. 221 7. On the LAN interface, there is no chance of address conflict 222 since the address is defended using DAD. The 3GPP radio 223 interface only has link-local addresses. 225 3.3 Scenario 3: A Single Global Address Assigned to 3GPP Radio and LAN 226 Interface 228 In this method, the UE assigns itself one address from the 3GPP 229 network RA announced /64. This one address is configured as anycast 230 [RFC4291] on both the 3GPP radio interface as a /128 and on the LAN 231 interface as a /64. This allows the UE to maintain long lived data 232 connections since the 3GPP radio interface address does not change 233 when the router function is activated. This method may cause 234 complications for certain software that may not support multiple 235 interfaces with the same anycast IPv6 address. This method also 236 creates complications for ensuring uniqueness for Privacy Extensions 237 [RFC4941]. Privacy Extensions should be disabled on the 3GPP radio 238 interface while this method is enabled. 240 Below is the general procedure for this scenario: 242 1. The user activates router functionality for a LAN on the UE. 244 2. The UE checks to make sure the 3GPP interfaces is active and has 245 an IPv6 address. If the interface does not have an IPv6 address, 246 an attempt will be made to acquire one, or else the procedure 247 will terminate. 249 3. In this example, the UE finds the 3GPP interface has the IPv6 250 address 2001:db8:ac10:f002:1234:4567:0:9 assigned and active. 252 4. The UE moves the address 2001:db8:ac10:f002:1234:4567:0:9 as an 253 anycast /64 from the 3GPP interface to the LAN interface and 254 begins announcing the prefix 2001:db8:ac10:f002::/64 via RA to 255 the LAN. The 3GPP interface maintains the same IPv6 anycast 256 address with a /128. For this example, the LAN has 257 2001:db8:ac10:f002:1234:4567:0:9/64 and the 3GPP radio interface 258 has 2001:db8:ac10:f002:1234:4567:0:9/128. 260 5. The UE directly processes all packets destine to itself at 261 2001:db8:ac10:f002:1234:4567:0:9. 263 6. On the LAN interface, there is no chance of address conflict 264 since the address is defended using DAD. The 3GPP radio 266 V6OPS Working Group draft-ietf-v6ops-64share-01 January 29, 2013 268 interface only has a /128 and no other systems on the 3GPP radio 269 point-to-point link may use the global /64. 271 4. Security Considerations 273 Security considerations identified in [I-D.draft-ietf-v6ops- 274 rfc3316bis] are to be taken into account. Since Scenario 3 does not 275 allow for Privacy Extension to run the 3GPP interface, UEs that 276 require this functionality must find an alternative method. 278 5. IANA Considerations 280 This document does not require any action from IANA. 282 6. Acknowledgments 284 Many thanks for review and discussion from Mark Smith, Dmitry Anipko, 285 Masanobu Kawashima, Teemu Savolainen, Mikael Abrahamsson, Eric 286 Vyncke, Alexandru Petrescu, Jouni Korhonen, Julien Laganier, and Ales 287 Vizdal. 289 7. Informative References 291 [I-D.ietf-v6ops-rfc3316bis] Korhonen, J., Arkko, J., Savolainen, T., 292 and S. Krishnan, "IPv6 for 3GPP Cellular Hosts", draft- 293 ietf-v6ops-rfc3316bis (work in progress), November 2012. 295 [RFC1981] McCann, J., Deering, S., and J. Mogul, "Path MTU Discovery 296 for IP version 6", RFC 1981, August 1996. 298 [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic 299 Host Configuration Protocol (DHCP) version 6", RFC 3633, 300 December 2003. 302 [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing 303 Architecture", RFC 4291, February 2006. 305 [RFC4389] Thaler, D., Talwar, M., and C. Patel, "Neighbor Discovery 306 Proxies (ND Proxy)", RFC 4389, April 2006. 308 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 309 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, 310 September 2007. 312 [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless 313 Address Autoconfiguration", RFC 4862, September 2007. 315 V6OPS Working Group draft-ietf-v6ops-64share-01 January 29, 2013 317 [RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy 318 Extensions for Stateless Address Autoconfiguration in 319 IPv6", RFC 4941, September 2007. 321 [RFC6459] Korhonen, J., Ed., Soininen, J., Patil, B., Savolainen, 322 T., Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation 323 Partnership Project (3GPP) Evolved Packet System (EPS)", 324 RFC 6459, January 2012. 326 Authors' Addresses 328 Cameron Byrne 329 T-Mobile USA 330 Bellevue, Washington, USA 332 EMail: Cameron.Byrne@T-Mobile.com 334 Dan Drown 335 Email: Dan@Drown.org