Network Working Group                                   B. Sarikaya, Ed.
Internet-Draft                                                Huawei USA
Intended status: Standards Track                          March 31, 2015
Expires: October 2, 2015

 Source Address Dependent Routing and Source Address Selection for IPv6


   This document presents the source address dependent routing from the
   host perspective.  Multihomed hosts and hosts with multiple
   interfaces are considered.  Different architectures are introduced
   and with their help, why source address selection and next hop
   resolution in view of source address dependent routing is needed is
   explained.  The document concludes with an informative guidelines on
   the different solution approaches.

Status of This Memo

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   This Internet-Draft will expire on October 2, 2015.

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   include Simplified BSD License text as described in Section 4.e of
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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  SADR Scenarios  . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Analysis of Source Address Dependent Routing  . . . . . . . .   8
     4.1.  Scenarios Analysis  . . . . . . . . . . . . . . . . . . .   8
     4.2.  Provisioning Domains and SADR . . . . . . . . . . . . . .  10
   5.  Guidelines on Standardization Work  . . . . . . . . . . . . .  10
     5.1.  Source Address Selection Rule 5.5 . . . . . . . . . . . .  11
     5.2.  Router Advertisement Option . . . . . . . . . . . . . . .  11
     5.3.  Router Advertisement Option Set . . . . . . . . . . . . .  12
     5.4.  Other Solutions . . . . . . . . . . . . . . . . . . . . .  12
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  13
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  13
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  13
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  13
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  15
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  16

1.  Introduction

   BCP 38 recommends ingress traffic routing to prohibit Denial of
   Service (DoS) attacks, i.e. datagrams which have source addresses
   that do not match with the network where the host is attached are
   discarded [RFC2827].  Avoiding packets to be dropped because of
   ingress filtering is difficult especially in multihomed networks
   where the host receives more than one prefix from the connected
   Internet Service Providers (ISP) and may have more than one source
   addresses.  Based on BCP 38, BCP 84 introduced recommendations on the
   routing system for multihomed networks [RFC3704].

   Recommendations on the routing system for ingress filtering such as
   in BCP 84 inevitably involve source address checks.  This leads us to
   the source address dependent routing.  Source address dependent
   routing is an issue especially when the host is connected to a
   multihomed network and is communicating with another host in another
   multihomed network.  In such a case, the communication can be broken
   in both directions if ISPs apply ingress filtering and the datagrams
   contain wrong source addresses

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   Hosts with simultaneously active interfaces receive multiple prefixes
   and have multiple source addresses.  Datagrams originating from such
   hosts carry greats risks to be dropped due to ingress filtering.
   Source address selection algorithm needs to be careful to try to
   avoid ingress filtering on the next-hop router [RFC6724].

   Many use cases have been reported for source/destination routing in
   [I-D.baker-rtgwg-src-dst-routing-use-cases].  These use cases clearly
   indicate that the multihomed host or Customer Premises Equipment
   (CPE) router needs to be configured with correct source prefixes/
   addresses so that it can route packets upstream correctly to avoid
   ingress filtering applied by an upstream ISP to drop the packets.

   In multihomed networks there is a need to do source address based
   routing if some providers are performing the ingress filtering
   defined in BCP38 [RFC2827].  This requires the routers to consider
   the source addresses as well as the destination addresses in
   determining the next hop to send the packet to.

   Based on the use cases defined in
   [I-D.baker-rtgwg-src-dst-routing-use-cases], the routers may be
   informed about the source addresses to use in routing using
   extensions to the routing protocols like IS-IS defined in
   [ISO.10589.1992] [I-D.baker-ipv6-isis-dst-src-routing] and OSPF
   defined in [RFC5340] [I-D.baker-ipv6-ospf-dst-src-routing].  In this
   document we describe the use cases for source address dependent
   routing from the host perspective.

   There are two cases.  A host may have a single interface with
   multiple addresses (from different prefixes or /64s).  Each address
   or prefix is connected to or coming from different exit routers, and
   this case can be called multi-prefix multihoming (MPMH).  A host may
   have simultaneously connected multiple interfaces where each
   interface is connected to a different exit router and this case can
   be called multi-prefix multiple interface (MPMI).

   It should be noted that Network Address and Port Translation (NAPT)
   [RFC3022] in IPv4 and IPv6-to-IPv6 Network Prefix Translation (NPTv6)
   [RFC6296] in IPv6 implement the functions of source address selection
   and next-hop resolution and as such they address multihoming (and
   hosts with multiple interfaces) requirements arising from source
   address dependent routing [RFC7157].  In this case, the gateway
   router or CPE router does the source address and next hop selection
   for all the hosts connected to the router.  However, for end-to-end
   connectivity, NAPT and NPTv6 should be avoided and because of this,
   NAPT and NPTv6 are left out of scope in this document.

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2.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in [RFC2119].

3.  SADR Scenarios

   Source address dependent routing can be facilitated at the host with
   proper next hop and source address selection.  For this, each router
   connected to different interfaces of the host uses Router
   Advertisements to distribute default route, next hop as well as
   source address/prefix information to the host.

   The use case shown in Figure 1 is multi-prefix multi interface use
   case where rtr1 and rtr2 represent customer premises equipment/
   routers (CPE) and there are exit routers in both network 1 and
   network 2.  The issue in this case is ingress filtering.  If the
   packets from the host communicating with a remote destination are
   routed to the wrong exit router, i.e. carry wrong source address,
   they will get dropped.

      +------+     +------+       ___________
      |      |     |      |      /           \
      |      |-----| rtr1 |=====/   network   \
      |      |     |      |     \      1      /
      |      |     +------+      \___________/
      |      |
      | host |
      |      |
      |      |     +------+       ___________
      |      |     |      |      /           \
      |      |=====| rtr2 |=====/   network   \
      |      |     |      |     \      2      /
      +------+     +------+      \___________/

          Figure 1: Multiple Interfaced Host with Two CPE Routers

   There is a variant of Figure 1 that is often referred to as a
   corporate VPN, i.e., a secure tunnel from the host to a router
   attached to a corporate network.  In this case rtr2 gives access
   directly to the corporate network, and the link from the host to rtr2
   is a secure tunnel (for example an IPsec tunnel).  The interface is
   therefore a virtual interface, with its own IP address assigned by
   the corporate network.

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         +------+     +------+       ___________
         |      |-----| rtr1 |      /           \
         |     ==========\\  |=====/   network   \
         |      |-----|  ||  |     \      1      /
         |      |     +--||--+      \___________/
         |      |        ||
         | host |        ||
         |      |        ||
         |      |     +--||--+       ___________
         |      |     |      |      / corporate \
         |      |     | rtr2 |=====/   network   \
         |      |     |      |     \      2      /
         +------+     +------+      \___________/

   There are at least two sub-cases: a) Host routes are created such
   that only traffic directed to the corporate network is sent to rtr2;
   everything else is sent to rtr2.  This case would be simplified by
   SADR, which could replace the host routes.

   b) All traffic is sent to rtr2 and then routed to the Internet if
   necessary.  This case doesn't need host routes but leads to
   unnecessary traffic and latency via rtr2.

   Our next use case is shown in Figure 2.  This use case is a multi-
   prefix multihoming use case. rtr is CPE router which is connected to
   two ISPs each advertising their own prefixes.  In this case, the host
   may have a single interface but it receives multiple prefixes from
   the connected ISPs.  Assuming that ISPs apply ingress filtering
   policy the packets for any external communication from the host
   should follow source address dependent routing in order to avoid
   getting dropped.

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      +------+                  |
      |      |                  |
      |      |                  |=====|(ISP1)|=====
      |      |     +------+     |
      |      |     |      |     |
      |      |=====| rtr  |=====|
      | host |     |      |     |
      |      |     +------+     |
      |      |                  |
      |      |                  |
      |      |                  |=====|(ISP2)|=====
      |      |                  |
      +------+                  |

            Figure 2: Multihomed Host with Multiple CPE Routers

   A variation of this use case is specialized egress routing.  Upstream
   networks offer different services with specific requirements, e.g.
   video service.  The hosts using this service need to use the
   service's source and destination addresses.  No other service will
   accept this source address, i.e. those packets will be dropped

    ___________                +------+
   /           \   +------+    |      |
  /   network   \  |      |    |      |
  \      1      /--| rtr1 |----|      |
   \___________/   |      |    |      |     +------+       ___________
                   +------+    | host |     |      |      /           \
                               |      |=====| rtr3 |=====/   network   \
    ___________                |      |     |      |     \      3      /
   /           \   +------+    |      |     +------+      \___________/
  /   network   \  |      |    |      |
  \      2      /--| rtr2 |----|      |
   \___________/   |      |    |      |
                   +------+    |      |

         Figure 3: multiple Interfaced Host with Three CPE Routers

   Next use case is shown in Figure 3.  It is a variation of multi-
   prefix multi interface use case above. rtr1, rtr2 and rtr3 are CPE
   Routers.  The networks apply ingress routing.  Source address
   dependent routing should be used to avoid any external communications
   be dropped.

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   In the homenet scenario given in Figure 4, representing a simple home
   network, there is a host connected to two CPEs which are connected to
   ISP1 and ISP2, respectively.  Each ISP provides a different prefix.
   Also each router provides a different prefix to the host.  The issue
   in this scenario is also ingress filtering used by each ISP.

      |      |     +------+
      |      |     |      |
      |      |==+==| rtr1 |=====|(ISP1)|=====
      |      |  |  |      |
      |      |  |  +------+
      | host |  |
      |      |  |
      |      |  |  +------+
      |      |  |  |      |
      |      |  +==| rtr2 |=====|(ISP2)|=====
      |      |     |      |
      +------+     +------+

            Figure 4: Simple Home Network with Two CPE Routers

   The host has to select the source address from the prefixes of ISP1
   or ISP2 when communicating with other hosts in ISP1 or ISP2.  The
   next issue is to select the correct next hop router, rtr1 or rtr2
   that can reach the right ISP, ISP1 or ISP2.

      +------+                  |     +------+
      |      |                  |     |      |
      |      |                  |-----| rtrF |=====ISP3
      |      |                  |     |      |
      |      |                  |     +------+
      |      |                  |
      | host |                  |
      |      |                  |
      |      |     +------+     |     +------+
      |      |     |      |     |     |      |===== ISP2
      |      |=====| rtr  |=====|=====| rtrE |
      |      |     |      |     |     |      |===== ISP1
      +------+     +------+     +     +------+

                   Figure 5: Shim6 Host with Two Routers

   The last use case in Figure 5 is also a variation of multi-prefix
   multihoming use case above.  In this case rtrE is connected to two
   ISPs.  All ISPs are assumed to apply ingress routing.  The host
   receives prefixes from each ISP and starts communicating with

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   external hosts, e.g.  H1, H2, etc.  H1 and H2 may be accessible both
   from ISP1 and ISP3.

   The host receives multiple provider-allocated IPv6 address prefixes,
   e.g.  P1, P2 and P3 for ISP1, ISP2 and ISP3 and supports shim6
   protocol [RFC5533]. rtr is a CPE router and the default router for
   the host. rtr receives OSPF routes and has a default route for rtrE
   and rtrF.

4.  Analysis of Source Address Dependent Routing

   In this section we present an analysis of the scenarios of Section 3
   and then discuss the relevance of SADR to the provisioning domains.

4.1.  Scenarios Analysis

   As in [RFC7157] we assume that the routers in Section 3 use Router
   Advertisements to distribute default route and source address
   prefixes supported in each next hop to the hosts or the gateway/CPE
   router relayes this information to the hosts.

   Referring to the scenario in Figure 1, source address dependent
   routing can present a solution to the problem of the host wishes to
   reach a destination in network 2 and the host may choose rtr1 as the
   default router.  The solution should start with the correct
   configuration of the host.  The host should be configured with the
   prefixes supported in these next hops.  This way the host having
   received many prefixes will have the correct knowledge in selecting
   the right source address and next hop when sending packets to remote

   Note that similar considerations apply to the scenario in Figure 3.

   In the configuration of the scenario in Figure 2 also it is useful to
   configure the host with the prefixes and source address prefixes they
   support.  This will enable the host to select the right prefix when
   sending packets to the right next hop and avoid any ingress

   Source address dependent routing in the use case of specialized
   egress routing may work as follows.  The specialized service router
   advertizes one or more specific prefixes with appropriate source
   prefixes, e.g. to the CPE Router, rtr in Figure 2.  The CPE router in
   turn advertizes the specific service's prefixes and source prefixes
   to the host.  This will allow proper configuration at the host so
   that the host can use the service by sending the packets with the
   correct source and destination addresses.

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   Let us analyze the use case in Figure 4.  If a source address
   dependent routing protocol is used, the two routers (rtr1 and rtr2)
   are both able to route traffic correctly, no matter which next-hop
   router and source address the host selects.  In case the host chooses
   the wrong next hop router, e.g. for ISP2 rtr1 is selected, rtr1 will
   forward the traffic to rtr2 to be sent to ISP2 and no ingress
   filtering will happen.

   Note that home networks are expected to comply with requirements for
   source address dependent routing and the routers will be configured
   accordingly, no matter which routing protocol, e.g.  OSPF is used

   This would work but with issues.  The host traffic to ISP2 will have
   to go over two links instead of one, i.e. the link bandwidth will be
   halved.  Another possibility is rtr1 can send an ICMPv6 Redirect
   message to the host to direct the traffic to rtr2.  Host would
   redirect ISP2 traffic to rtr2.

   The problem with redirects is that ICMPv6 Redirect message can only
   convey two addresses, i.e. in this case the router address, or rtr2
   address and the destination address, or the destination host in ISP2.
   That means the source address will not be communicated.  As a result,
   the host would send packets to the same destination using both source
   addresses which causes rtr2 to send a redirect message to rtr1,
   resulting in ping-pong redirects sent by rtr1 and rtr2.

   The best solution to these issues is to configure the host with the
   source address prefixes that the next hop supports.  In homenets,
   each interface of the host can be configured by its next hop router,
   so that all that is needed is to add the information on source
   address prefixes.  This results in the hosts to select the right
   router no matter what.

   Finally, the use case in Figure 5 shows that even though all the
   routers may have source address dependent routing support, the
   packets still may get dropped.

   The host in Figure 5 starts external communication with H1 and sends
   the first packet with source address P3::iid.  Since rtr has a
   default route to rtrE it will use this default route in sending the
   host's packet out towards rtrE. rtrE will route this packet to ISP1
   and the packet will be dropped due to the ingress filtering.

   A solution to this issue could be that rtrE having multiple routes to
   H1 could use the path through rtrF and could direct the packet to the
   other route, i.e. rtrF which would reach H1 in ISP3 without being

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   subject to ingress routing

4.2.  Provisioning Domains and SADR

   Consistent set of network configuration information is called
   provisioning domain (PvD).  In case of multi-prefix multihoming
   (MPMH), more than one provisioning domain is present on a single
   link.  In case of multi-prefix multiple interface (MPMI)
   environments, elements of the same domain may be present on multiple
   links.  PvD aware nodes support association of configuration
   information into PvDs and use these PvDs to serve requests for
   network connections, e.g. chosing the right source address for the
   packets.  PvDs can be constructed from one of more DHCP or Router
   Advertisement (RA) options carrying such information as PvD identity
   and PvD container [I-D.ietf-mif-mpvd-ndp-support],
   [I-D.ietf-mif-mpvd-dhcp-support].  PvDs constructed based on such
   information are called explicit PvDs [I-D.ietf-mif-mpvd-arch].

   Apart from PvD identity, PvD content may be encapsulated in separate
   RA or DHCP options called PvD Container Option.  Examples of such
   content are defined in [I-D.sarikaya-6man-sadr-ra] and
   [I-D.sarikaya-dhc-6man-dhcpv6-sadr].  These options are placed in the
   container options of an explicit PvD.

   Explicit PvDs may be received from different interfaces.  Single PvD
   may be accessible over one interface or simulatenously accessible
   over multiple interfaces.  Explicit PvDs may be scoped to a
   configuration related to a particular interface, however in general
   this may not apply.  What matters is PvD ID provided that PvD ID is
   authenticated by the node even in cases where the node has a single
   connected interface.  The authentication of the PvD ID should meet
   the level required by the node policy.  Single PvD information may be
   received over multiple interfaces as long as PvD ID is the same.
   This applies to the router advertisements (RAs) in which case a
   multi-homed host (that is, with multiple interfaces) should trust a
   message from a router on one interface to install a route to a
   different router on another interface.

5.  Guidelines on Standardization Work

   We presented many topologies in which a host with multiple interfaces
   or a multihomed host is connected to various networks or ISPs which
   in turn may apply ingress routing.  Our scenario analysis showed that
   in order to avoid packets getting dropped due to ingress routing,
   source address dependent routing is needed.  Also, source address
   dependent routing should be supported by routers throughout a site
   that has multiple exits.

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   In this section, we provide informative guidelines on different
   existing and future solutions vis a vis the scenarios presented in
   Section 3.  We start with source address selection rule 5.5 and the
   scenarios it solves and continue with solutions that state exactly
   what information hosts need in terms of new router advertisement
   options for correct source address selection in those scenarios.

5.1.  Source Address Selection Rule 5.5

   One possible solution is the default source address selection Rule
   5.5 in [RFC6724] which recommends to select source addresses
   advertized by the next hop.  Considering the above scenarios, we can
   state that this rule can solve the problem in Figure 1, Figure 2 and
   Figure 3.

   In using Rule 5.5 the following guidelines should be kept in mind.
   Source address selection rules can be distributed by DHCP server
   using DHCP Option OPTION_ADDRSEL_TABLE defined in [RFC7078].

   In case of DHCP based host configuration, DHCP server can configure
   only the interface of the host to which it is directly connected.  In
   order for Rule 5.5 to apply on other interfaces the option should be
   sent on those interfaces as well using [RFC7078].

   The default source address selection Rule 5.5 solves that problem
   when an application sends a packet with an unspecified source
   address.  In the presence of two default routes, one route will be
   chosen, and Rule 5.5 will make sure the right source address is used.

   When the application selects a source address, i.e. the source
   address is chosen before next-hop selection, even though the source
   address is a way for the application to select the exit point, in
   this case that purpose will not be served.  In the presence of
   multiple default routes, one will be picked, ignoring the source
   address which was selected by the application because it is known
   that IPv6 implementations are not required to remember which next-
   hops advertised which prefixes.  Therefore, the next-hop router may
   not be the correct one, and the packets may be filtered.

   This implies that the hosts should register which next-hop router
   announced each prefix.

5.2.  Router Advertisement Option

   There is a need to configure the host not only with the prefixes but
   also with the source prefixes the next hop routers support.  Such a
   configuration may avoid the host getting ingress/egress policy error
   messages such as ICMP source address failure message.

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   If host configuration is done using router advertisement messages
   then there is a need to define new router advertisement options for
   source address dependent routing.  These options include Route Prefix
   with Source Address/Prefix Option.  Other options such as Next Hop
   Address with Route Prefix option and Next Hop Address with Source
   Address and Route Prefix option will be considered in Section 5.3.

   As we observed in Section 4.1, the scenario in Figure 4 can be solved
   by defining a new router advertisement option, i.e. Route Prefix with
   Source Address/Prefix Option as defined in

   If host configuration is done using DHCP then there is a need to
   define new DHCP options for Route Prefix with Source Address/Prefix.
   As mentioned above, DHCP server configuration is interface specific.
   New DHCP options for source address dependent routing such as route
   prefix and source prefix need to be configured for each interface

   The scenario in Figure 4 can be solved by defining a new DHCP option,
   i.e. Route Prefix with Source Address/Prefix Option, if DHCP
   configuration is a must [I-D.sarikaya-dhc-6man-dhcpv6-sadr].

5.3.  Router Advertisement Option Set

   The source address selection rule 5.5 may possibly be a solution for
   selecting the right source addresses for each next hop but there are
   cases where the next hop routers on each interface of the host are
   not known by the host initially.  Such use cases are out of scope.
   Guidelines for use cases that require router advertisement option set
   involving third party next hop addresses are also out of scope.

5.4.  Other Solutions

   So far we have singled out the scenario in Figure 5.  All the above
   solutions do not work in this case.  This brings us the issue of IP
   path probing [I-D.naderi-ipv6-probing].

   For a given destination, the host selects a source address and a next
   hop and sends its packet.  When the selected path fails, in case of
   IP probing, the host can probe all available paths until finding one
   that works.

   The guideline in probing is Source Address Dependent Routing (SADR)
   should be used, i.e. it is a necessary tool.  Basically, SADR saves
   time in eliminating wrong paths, i.e. sending the packets to the
   wrong exit router.  If SADR is not taken into account correctly the

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   host will end up wasting resources trying to explore paths that are
   certain to fail.

6.  Security Considerations

   This document describes some use cases and thus brings no new
   security risks to the Internet.

7.  IANA Considerations


8.  Acknowledgements

   In writing this document, we benefited from the ideas expressed by
   the electronic mail discussion participants on 6man Working Group:
   Brian Carpenter, Ole Troan, Pierre Pfister, Alex Petrescu, Ray
   Hunter, Lorenzo Colitti and others.  Pierre Pfister proposed the
   scenario in Figure 4 as well as some text for Rule 5.5.  The text on
   corporate VPN in Section 3 was provided by Brian Carpenter.

9.  References

9.1.  Normative References

              Stenberg, M., Barth, S., and P. Pfister, "Home Networking
              Control Protocol", draft-ietf-homenet-hncp-04 (work in
              progress), March 2015.

              International Organization for Standardization,
              "Intermediate system to intermediate system intra-domain-
              routing routine information exchange protocol for use in
              conjunction with the protocol for providing the
              connectionless-mode Network Service (ISO 8473), ISO
              Standard 10589", ISO ISO.10589.1992, 1992.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2629]  Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
              June 1999.

   [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.

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   [RFC3022]  Srisuresh, P. and K. Egevang, "Traditional IP Network
              Address Translator (Traditional NAT)", RFC 3022, January

   [RFC3704]  Baker, F. and P. Savola, "Ingress Filtering for Multihomed
              Networks", BCP 84, RFC 3704, March 2004.

   [RFC3971]  Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure
              Neighbor Discovery (SEND)", RFC 3971, March 2005.

   [RFC4191]  Draves, R. and D. Thaler, "Default Router Preferences and
              More-Specific Routes", RFC 4191, November 2005.

   [RFC4605]  Fenner, B., He, H., Haberman, B., and H. Sandick,
              "Internet Group Management Protocol (IGMP) / Multicast
              Listener Discovery (MLD)-Based Multicast Forwarding
              ("IGMP/MLD Proxying")", RFC 4605, August 2006.

   [RFC4861]  Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
              "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
              September 2007.

   [RFC4862]  Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
              Address Autoconfiguration", RFC 4862, September 2007.

   [RFC5340]  Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
              for IPv6", RFC 5340, July 2008.

   [RFC5533]  Nordmark, E. and M. Bagnulo, "Shim6: Level 3 Multihoming
              Shim Protocol for IPv6", RFC 5533, June 2009.

   [RFC6106]  Jeong, J., Park, S., Beloeil, L., and S. Madanapalli,
              "IPv6 Router Advertisement Options for DNS Configuration",
              RFC 6106, November 2010.

   [RFC6296]  Wasserman, M. and F. Baker, "IPv6-to-IPv6 Network Prefix
              Translation", RFC 6296, June 2011.

   [RFC6724]  Thaler, D., Draves, R., Matsumoto, A., and T. Chown,
              "Default Address Selection for Internet Protocol Version 6
              (IPv6)", RFC 6724, September 2012.

   [RFC7078]  Matsumoto, A., Fujisaki, T., and T. Chown, "Distributing
              Address Selection Policy Using DHCPv6", RFC 7078, January

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   [RFC7157]  Troan, O., Miles, D., Matsushima, S., Okimoto, T., and D.
              Wing, "IPv6 Multihoming without Network Address
              Translation", RFC 7157, March 2014.

9.2.  Informative References

              Baker, F., "Multiprefix IPv6 Routing for Ingress Filters",
              draft-baker-6man-multiprefix-default-route-00 (work in
              progress), November 2007.

              Baker, F. and D. Lamparter, "IPv6 Source/Destination
              Routing using IS-IS", draft-baker-ipv6-isis-dst-src-
              routing-02 (work in progress), October 2014.

              Baker, F., "IPv6 Source/Destination Routing using OSPFv3",
              draft-baker-ipv6-ospf-dst-src-routing-03 (work in
              progress), August 2013.

              Baker, F., "Requirements and Use Cases for Source/
              Destination Routing", draft-baker-rtgwg-src-dst-routing-
              use-cases-01 (work in progress), October 2014.

              Huitema, C., "Ingress filtering compatibility for IPv6
              multihomed sites", draft-huitema-multi6-ingress-
              filtering-00 (work in progress), October 2004.

              Anipko, D., "Multiple Provisioning Domain Architecture",
              draft-ietf-mif-mpvd-arch-11 (work in progress), March

              Krishnan, S., Korhonen, J., and S. Bhandari, "Support for
              multiple provisioning domains in DHCPv6", draft-ietf-mif-
              mpvd-dhcp-support-01 (work in progress), March 2015.

              Korhonen, J., Krishnan, S., and S. Gundavelli, "Support
              for multiple provisioning domains in IPv6 Neighbor
              Discovery Protocol", draft-ietf-mif-mpvd-ndp-support-01
              (work in progress), February 2015.

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              Naderi, H. and B. Carpenter, "Experience with IPv6 path
              probing", draft-naderi-ipv6-probing-00 (work in progress),
              October 2014.

              Sarikaya, B., "IPv6 RA Options for Source Address
              Dependent Routing", draft-sarikaya-6man-sadr-ra-00 (work
              in progress), March 2015.

              Sarikaya, B., "DHCPv6 Route Options for Source Address
              Dependent Routing", draft-sarikaya-dhc-6man-dhcpv6-sadr-00
              (work in progress), December 2014.

Author's Address

   Behcet Sarikaya (editor)
   Huawei USA
   5340 Legacy Dr. Building 175
   Plano, TX  75024


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