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diff --git a/src/vnet/sr/ietf_draft_05.txt b/src/vnet/sr/ietf_draft_05.txt new file mode 100755 index 00000000000..e9bff04fa0a --- /dev/null +++ b/src/vnet/sr/ietf_draft_05.txt @@ -0,0 +1,1564 @@ +Network Working Group S. Previdi, Ed. +Internet-Draft C. Filsfils +Intended status: Standards Track Cisco Systems, Inc. +Expires: August 5, 2017 B. Field + Comcast + I. Leung + Rogers Communications + J. Linkova + Google + E. Aries + Facebook + T. Kosugi + NTT + E. Vyncke + Cisco Systems, Inc. + D. Lebrun + Universite Catholique de Louvain + February 1, 2017 + + + IPv6 Segment Routing Header (SRH) + draft-ietf-6man-segment-routing-header-05 + +Abstract + + Segment Routing (SR) allows a node to steer a packet through a + controlled set of instructions, called segments, by prepending an SR + header to the packet. A segment can represent any instruction, + topological or service-based. SR allows to enforce a flow through + any path (topological, or application/service based) while + maintaining per-flow state only at the ingress node to the SR domain. + + Segment Routing can be applied to the IPv6 data plane with the + addition of a new type of Routing Extension Header. This draft + describes the Segment Routing Extension Header Type and how it is + used by SR capable nodes. + +Requirements Language + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this + document are to be interpreted as described in RFC 2119 [RFC2119]. + +Status of This Memo + + This Internet-Draft is submitted in full conformance with the + provisions of BCP 78 and BCP 79. + + + + +Previdi, et al. Expires August 5, 2017 [Page 1] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + Internet-Drafts are working documents of the Internet Engineering + Task Force (IETF). Note that other groups may also distribute + working documents as Internet-Drafts. The list of current Internet- + Drafts is at http://datatracker.ietf.org/drafts/current/. + + 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." + + This Internet-Draft will expire on August 5, 2017. + +Copyright Notice + + Copyright (c) 2017 IETF Trust and the persons identified as the + document authors. All rights reserved. + + This document is subject to BCP 78 and the IETF Trust's Legal + Provisions Relating to IETF Documents + (http://trustee.ietf.org/license-info) in effect on the date of + publication of this document. Please review these documents + carefully, as they describe your rights and restrictions with respect + to this document. Code Components extracted from this document must + include Simplified BSD License text as described in Section 4.e of + the Trust Legal Provisions and are provided without warranty as + described in the Simplified BSD License. + +Table of Contents + + 1. Segment Routing Documents . . . . . . . . . . . . . . . . . . 3 + 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 + 2.1. Data Planes supporting Segment Routing . . . . . . . . . 4 + 2.2. Segment Routing (SR) Domain . . . . . . . . . . . . . . . 4 + 2.2.1. SR Domain in a Service Provider Network . . . . . . . 5 + 2.2.2. SR Domain in a Overlay Network . . . . . . . . . . . 6 + 3. Segment Routing Extension Header (SRH) . . . . . . . . . . . 7 + 3.1. SRH TLVs . . . . . . . . . . . . . . . . . . . . . . . . 9 + 3.1.1. Ingress Node TLV . . . . . . . . . . . . . . . . . . 10 + 3.1.2. Egress Node TLV . . . . . . . . . . . . . . . . . . . 11 + 3.1.3. Opaque Container TLV . . . . . . . . . . . . . . . . 11 + 3.1.4. Padding TLV . . . . . . . . . . . . . . . . . . . . . 12 + 3.1.5. HMAC TLV . . . . . . . . . . . . . . . . . . . . . . 13 + 3.2. SRH and RFC2460 behavior . . . . . . . . . . . . . . . . 14 + 4. SRH Procedures . . . . . . . . . . . . . . . . . . . . . . . 14 + 4.1. Source SR Node . . . . . . . . . . . . . . . . . . . . . 14 + 4.2. Transit Node . . . . . . . . . . . . . . . . . . . . . . 15 + 4.3. SR Segment Endpoint Node . . . . . . . . . . . . . . . . 16 + 5. Security Considerations . . . . . . . . . . . . . . . . . . . 16 + + + +Previdi, et al. Expires August 5, 2017 [Page 2] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + 5.1. Threat model . . . . . . . . . . . . . . . . . . . . . . 17 + 5.1.1. Source routing threats . . . . . . . . . . . . . . . 17 + 5.1.2. Applicability of RFC 5095 to SRH . . . . . . . . . . 17 + 5.1.3. Service stealing threat . . . . . . . . . . . . . . . 18 + 5.1.4. Topology disclosure . . . . . . . . . . . . . . . . . 18 + 5.1.5. ICMP Generation . . . . . . . . . . . . . . . . . . . 18 + 5.2. Security fields in SRH . . . . . . . . . . . . . . . . . 19 + 5.2.1. Selecting a hash algorithm . . . . . . . . . . . . . 20 + 5.2.2. Performance impact of HMAC . . . . . . . . . . . . . 21 + 5.2.3. Pre-shared key management . . . . . . . . . . . . . . 21 + 5.3. Deployment Models . . . . . . . . . . . . . . . . . . . . 22 + 5.3.1. Nodes within the SR domain . . . . . . . . . . . . . 22 + 5.3.2. Nodes outside of the SR domain . . . . . . . . . . . 22 + 5.3.3. SR path exposure . . . . . . . . . . . . . . . . . . 23 + 5.3.4. Impact of BCP-38 . . . . . . . . . . . . . . . . . . 23 + 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24 + 7. Manageability Considerations . . . . . . . . . . . . . . . . 24 + 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 24 + 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 24 + 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 25 + 10.1. Normative References . . . . . . . . . . . . . . . . . . 25 + 10.2. Informative References . . . . . . . . . . . . . . . . . 25 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27 + +1. Segment Routing Documents + + Segment Routing terminology is defined in + [I-D.ietf-spring-segment-routing]. + + Segment Routing use cases are described in [RFC7855] and + [I-D.ietf-spring-ipv6-use-cases]. + + Segment Routing protocol extensions are defined in + [I-D.ietf-isis-segment-routing-extensions], and + [I-D.ietf-ospf-ospfv3-segment-routing-extensions]. + +2. Introduction + + Segment Routing (SR), defined in [I-D.ietf-spring-segment-routing], + allows a node to steer a packet through a controlled set of + instructions, called segments, by prepending an SR header to the + packet. A segment can represent any instruction, topological or + service-based. SR allows to enforce a flow through any path + (topological or service/application based) while maintaining per-flow + state only at the ingress node to the SR domain. Segments can be + derived from different components: IGP, BGP, Services, Contexts, + Locators, etc. The list of segment forming the path is called the + Segment List and is encoded in the packet header. + + + +Previdi, et al. Expires August 5, 2017 [Page 3] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + SR allows the use of strict and loose source based routing paradigms + without requiring any additional signaling protocols in the + infrastructure hence delivering an excellent scalability property. + + The source based routing model described in + [I-D.ietf-spring-segment-routing] is inherited from the ones proposed + by [RFC1940] and [RFC2460]. The source based routing model offers + the support for explicit routing capability. + +2.1. Data Planes supporting Segment Routing + + Segment Routing (SR), can be instantiated over MPLS + ([I-D.ietf-spring-segment-routing-mpls]) and IPv6. This document + defines its instantiation over the IPv6 data-plane based on the use- + cases defined in [I-D.ietf-spring-ipv6-use-cases]. + + This document defines a new type of Routing Header (originally + defined in [RFC2460]) called the Segment Routing Header (SRH) in + order to convey the Segment List in the packet header as defined in + [I-D.ietf-spring-segment-routing]. Mechanisms through which segment + are known and advertised are outside the scope of this document. + + A segment is materialized by an IPv6 address. A segment identifies a + topological instruction or a service instruction. A segment can be + either: + + o global: a global segment represents an instruction supported by + all nodes in the SR domain and it is instantiated through an IPv6 + address globally known in the SR domain. + + o local: a local segment represents an instruction supported only by + the node who originates it and it is instantiated through an IPv6 + address that is known only by the local node. + +2.2. Segment Routing (SR) Domain + + We define the concept of the Segment Routing Domain (SR Domain) as + the set of nodes participating into the source based routing model. + These nodes may be connected to the same physical infrastructure + (e.g.: a Service Provider's network) as well as nodes remotely + connected to each other (e.g.: an enterprise VPN or an overlay). + + A non-exhaustive list of examples of SR Domains is: + + o The network of an operator, service provider, content provider, + enterprise including nodes, links and Autonomous Systems. + + + + + +Previdi, et al. Expires August 5, 2017 [Page 4] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + o A set of nodes connected as an overlay over one or more transit + providers. The overlay nodes exchange SR-enabled traffic with + segments belonging solely to the overlay routers (the SR domain). + None of the segments in the SR-enabled packets exchanged by the + overlay belong to the transit networks + + The source based routing model through its instantiation of the + Segment Routing Header (SRH) defined in this document equally applies + to all the above examples. + + It is assumed in this document that the SRH is added to the packet by + its source, consistently with the source routing model defined in + [RFC2460]. For example: + + o At the node originating the packet (host, server). + + o At the ingress node of an SR domain where the ingress node + receives an IPv6 packet and encapsulates it into an outer IPv6 + header followed by a Segment Routing header. + +2.2.1. SR Domain in a Service Provider Network + + The following figure illustrates an SR domain consisting of an + operator's network infrastructure. + + (-------------------------- Operator 1 -----------------------) + ( ) + ( (-----AS 1-----) (-------AS 2-------) (----AS 3-------) ) + ( ( ) ( ) ( ) ) + A1--(--(--11---13--14-)--(-21---22---23--24-)--(-31---32---34--)--)--Z1 + ( ( /|\ /|\ /| ) ( |\ /|\ /|\ /| ) ( |\ /|\ /| \ ) ) + A2--(--(/ | \/ | \/ | ) ( | \/ | \/ | \/ | ) ( | \/ | \/ | \)--)--Z2 + ( ( | /\ | /\ | ) ( | /\ | /\ | /\ | ) ( | /\ | /\ | ) ) + ( ( |/ \|/ \| ) ( |/ \|/ \|/ \| ) ( |/ \|/ \| ) ) + A3--(--(--15---17--18-)--(-25---26---27--28-)--(-35---36---38--)--)--Z3 + ( ( ) ( ) ( ) ) + ( (--------------) (------------------) (---------------) ) + ( ) + (-------------------------------------------------------------) + + Figure 1: Service Provider SR Domain + + Figure 1 describes an operator network including several ASes and + delivering connectivity between endpoints. In this scenario, Segment + Routing is used within the operator networks and across the ASes + boundaries (all being under the control of the same operator). In + this case segment routing can be used in order to address use cases + such as end-to-end traffic engineering, fast re-route, egress peer + + + +Previdi, et al. Expires August 5, 2017 [Page 5] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + engineering, data-center traffic engineering as described in + [RFC7855], [I-D.ietf-spring-ipv6-use-cases] and + [I-D.ietf-spring-resiliency-use-cases]. + + Typically, an IPv6 packet received at ingress (i.e.: from outside the + SR domain), is classified according to network operator policies and + such classification results into an outer header with an SRH applied + to the incoming packet. The SRH contains the list of segment + representing the path the packet must take inside the SR domain. + Thus, the SA of the packet is the ingress node, the DA (due to SRH + procedures described in Section 4) is set as the first segment of the + path and the last segment of the path is the egress node of the SR + domain. + + The path may include intra-AS as well as inter-AS segments. It has + to be noted that all nodes within the SR domain are under control of + the same administration. When the packet reaches the egress point of + the SR domain, the outer header and its SRH are removed so that the + destination of the packet is unaware of the SR domain the packet has + traversed. + + The outer header with the SRH is no different from any other + tunneling encapsulation mechanism and allows a network operator to + implement traffic engineering mechanisms so to efficiently steer + traffic across his infrastructure. + +2.2.2. SR Domain in a Overlay Network + + The following figure illustrates an SR domain consisting of an + overlay network over multiple operator's networks. + + (--Operator 1---) (-----Operator 2-----) (--Operator 3---) + ( ) ( ) ( ) + A1--(--11---13--14--)--(--21---22---23--24--)--(-31---32---34--)--C1 + ( /|\ /|\ /| ) ( |\ /|\ /|\ /| ) ( |\ /|\ /| \ ) + A2--(/ | \/ | \/ | ) ( | \/ | \/ | \/ | ) ( | \/ | \/ | \)--C2 + ( | /\ | /\ | ) ( | /\ | /\ | /\ | ) ( | /\ | /\ | ) + ( |/ \|/ \| ) ( |/ \|/ \|/ \| ) ( |/ \|/ \| ) + A3--(--15---17--18--)--(--25---26---27--28--)--(-35---36---38--)--C3 + ( ) ( | | | ) ( ) + (---------------) (--|----|---------|--) (---------------) + | | | + B1 B2 B3 + + Figure 2: Overlay SR Domain + + + + + + +Previdi, et al. Expires August 5, 2017 [Page 6] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + Figure 2 describes an overlay consisting of nodes connected to three + different network operators and forming a single overlay network + where Segment routing packets are exchanged. + + The overlay consists of nodes A1, A2, A3, B1, B2, B3, C1, C2 and C3. + These nodes are connected to their respective network operator and + form an overlay network. + + Each node may originate packets with an SRH which contains, in the + segment list of the SRH or in the DA, segments identifying other + overlay nodes. This implies that packets with an SRH may traverse + operator's networks but, obviously, these SRHs cannot contain an + address/segment of the transit operators 1, 2 and 3. The SRH + originated by the overlay can only contain address/segment under the + administration of the overlay (e.g. address/segments supported by A1, + A2, A3, B1, B2, B3, C1,C2 or C3). + + In this model, the operator network nodes are transit nodes and, + according to [RFC2460], MUST NOT inspect the routing extension header + since they are not the DA of the packet. + + It is a common practice in operators networks to filter out, at + ingress, any packet whose DA is the address of an internal node and + it is also possible that an operator would filter out any packet + destined to an internal address and having an extension header in it. + + This common practice does not impact the SR-enabled traffic between + the overlay nodes as the intermediate transit networks never see a + destination address belonging to their infrastructure. These SR- + enabled overlay packets will thus never be filtered by the transit + operators. + + In all cases, transit packets (i.e.: packets whose DA is outside the + domain of the operator's network) will be forwarded accordingly + without introducing any security concern in the operator's network. + This is similar to tunneled packets. + +3. Segment Routing Extension Header (SRH) + + A new type of the Routing Header (originally defined in [RFC2460]) is + defined: the Segment Routing Header (SRH) which has a new Routing + Type, (suggested value 4) to be assigned by IANA. + + The Segment Routing Header (SRH) is defined as follows: + + + + + + + +Previdi, et al. Expires August 5, 2017 [Page 7] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Next Header | Hdr Ext Len | Routing Type | Segments Left | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | First Segment | Flags | RESERVED | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | Segment List[0] (128 bits IPv6 address) | + | | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | | + ... + | | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | Segment List[n] (128 bits IPv6 address) | + | | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + // // + // Optional Type Length Value objects (variable) // + // // + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + where: + + o Next Header: 8-bit selector. Identifies the type of header + immediately following the SRH. + + o Hdr Ext Len: 8-bit unsigned integer, is the length of the SRH + header in 8-octet units, not including the first 8 octets. + + o Routing Type: TBD, to be assigned by IANA (suggested value: 4). + + o Segments Left. Defined in [RFC2460], it contains the index, in + the Segment List, of the next segment to inspect. Segments Left + is decremented at each segment. + + o First Segment: contains the index, in the Segment List, of the + first segment of the path which is in fact the last element of the + Segment List. + + o Flags: 8 bits of flags. Following flags are defined: + + + + +Previdi, et al. Expires August 5, 2017 [Page 8] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + 0 1 2 3 4 5 6 7 + +-+-+-+-+-+-+-+-+ + |U|P|O|A|H| U | + +-+-+-+-+-+-+-+-+ + + U: Unused and for future use. SHOULD be unset on transmission + and MUST be ignored on receipt. + + P-flag: Protected flag. Set when the packet has been rerouted + through FRR mechanism by an SR endpoint node. + + O-flag: OAM flag. When set, it indicates that this packet is + an operations and management (OAM) packet. + + A-flag: Alert flag. If present, it means important Type Length + Value (TLV) objects are present. See Section 3.1 for details + on TLVs objects. + + H-flag: HMAC flag. If set, the HMAC TLV is present and is + encoded as the last TLV of the SRH. In other words, the last + 36 octets of the SRH represent the HMAC information. See + Section 3.1.5 for details on the HMAC TLV. + + o RESERVED: SHOULD be unset on transmission and MUST be ignored on + receipt. + + o Segment List[n]: 128 bit IPv6 addresses representing the nth + segment in the Segment List. The Segment List is encoded starting + from the last segment of the path. I.e., the first element of the + segment list (Segment List [0]) contains the last segment of the + path while the last segment of the Segment List (Segment List[n]) + contains the first segment of the path. The index contained in + "Segments Left" identifies the current active segment. + + o Type Length Value (TLV) are described in Section 3.1. + +3.1. SRH TLVs + + This section defines TLVs of the Segment Routing Header. + + Type Length Value (TLV) contain optional information that may be used + by the node identified in the DA of the packet. It has to be noted + that the information carried in the TLVs is not intended to be used + by the routing layer. Typically, TLVs carry information that is + consumed by other components (e.g.: OAM) than the routing function. + + Each TLV has its own length, format and semantic. The code-point + allocated (by IANA) to each TLV defines both the format and the + + + +Previdi, et al. Expires August 5, 2017 [Page 9] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + semantic of the information carried in the TLV. Multiple TLVs may be + encoded in the same SRH. + + The "Length" field of the TLV is primarily used to skip the TLV while + inspecting the SRH in case the node doesn't support or recognize the + TLV codepoint. The "Length" defines the TLV length in octets and not + including the "Type" and "Length" fields. + + The primary scope of TLVs is to give the receiver of the packet + information related to the source routed path (e.g.: where the packet + entered in the SR domain and where it is expected to exit). + + Additional TLVs may be defined in the future. + +3.1.1. Ingress Node TLV + + The Ingress Node TLV is optional and identifies the node this packet + traversed when entered the SR domain. The Ingress Node TLV has + following format: + + 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 | RESERVED | Flags | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | Ingress Node (16 octets) | + | | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + where: + + o Type: to be assigned by IANA (suggested value 1). + + o Length: 18. + + o RESERVED: 8 bits. SHOULD be unset on transmission and MUST be + ignored on receipt. + + o Flags: 8 bits. No flags are defined in this document. + + o Ingress Node: 128 bits. Defines the node where the packet is + expected to enter the SR domain. In the encapsulation case + described in Section 2.2.1, this information corresponds to the SA + of the encapsulating header. + + + + + +Previdi, et al. Expires August 5, 2017 [Page 10] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + +3.1.2. Egress Node TLV + + The Egress Node TLV is optional and identifies the node this packet + is expected to traverse when exiting the SR domain. The Egress Node + TLV has following format: + + 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 | RESERVED | Flags | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | Egress Node (16 octets) | + | | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + where: + + o Type: to be assigned by IANA (suggested value 2). + + o Length: 18. + + o RESERVED: 8 bits. SHOULD be unset on transmission and MUST be + ignored on receipt. + + o Flags: 8 bits. No flags are defined in this document. + + o Egress Node: 128 bits. Defines the node where the packet is + expected to exit the SR domain. In the encapsulation case + described in Section 2.2.1, this information corresponds to the + last segment of the SRH in the encapsulating header. + +3.1.3. Opaque Container TLV + + The Opaque Container TLV is optional and has the following format: + + + + + + + + + + + + + + + +Previdi, et al. Expires August 5, 2017 [Page 11] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + 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 | RESERVED | Flags | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + | Opaque Container (16 octets) | + | | + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + where: + + o Type: to be assigned by IANA (suggested value 3). + + o Length: 18. + + o RESERVED: 8 bits. SHOULD be unset on transmission and MUST be + ignored on receipt. + + o Flags: 8 bits. No flags are defined in this document. + + o Opaque Container: 128 bits of opaque data not relevant for the + routing layer. Typically, this information is consumed by a non- + routing component of the node receiving the packet (i.e.: the node + in the DA). + +3.1.4. Padding TLV + + The Padding TLV is optional and with the purpose of aligning the SRH + on a 8 octet boundary. The Padding TLV has the following format: + + 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 | Padding (variable) | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + // Padding (variable) // + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + where: + + o Type: to be assigned by IANA (suggested value 4). + + o Length: 1 to 7 + + + + + + +Previdi, et al. Expires August 5, 2017 [Page 12] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + o Padding: from 1 to 7 octets of padding. Padding bits have no + semantic. They SHOULD be set to 0 on transmission and MUST be + ignored on receipt. + + The following applies to the Padding TLV: + + o Padding TLV is optional and MAY only appear once in the SRH. If + present, it MUST have a length between 1 and 7 octets. + + o The Padding TLV is used in order to align the SRH total length on + the 8 octet boundary. + + o When present, the Padding TLV MUST appear as the last TLV before + the HMAC TLV (if HMAC TLV is present). + + o When present, the Padding TLV MUST have a length from 1 to 7 in + order to align the SRH total lenght on a 8-octet boundary. + + o When a router inspecting the SRH encounters the Padding TLV, it + MUST assume that no other TLV (other than the HMAC) follow the + Padding TLV. + +3.1.5. HMAC TLV + + HMAC TLV is optional and contains the HMAC information. The HMAC TLV + has the following format: + + 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 | RESERVED | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | HMAC Key ID (4 octets) | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | // + | HMAC (32 octets) // + | // + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + where: + + o Type: to be assigned by IANA (suggested value 5). + + o Length: 38. + + o RESERVED: 2 octets. SHOULD be unset on transmission and MUST be + ignored on receipt. + + + + +Previdi, et al. Expires August 5, 2017 [Page 13] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + o HMAC Key ID: 4 octets. + + o HMAC: 32 octets. + + o HMAC and HMAC Key ID usage is described in Section 5 + + The Following applies to the HMAC TLV: + + o When present, the HMAC TLV MUST be encoded as the last TLV of the + SRH. + + o If the HMAC TLV is present, the SRH H-Flag (Figure 4) MUST be set. + + o When the H-flag is set in the SRH, the router inspecting the SRH + MUST find the HMAC TLV in the last 38 octets of the SRH. + +3.2. SRH and RFC2460 behavior + + The SRH being a new type of the Routing Header, it also has the same + properties: + + SHOULD only appear once in the packet. + + Only the router whose address is in the DA field of the packet + header MUST inspect the SRH. + + Therefore, Segment Routing in IPv6 networks implies that the segment + identifier (i.e.: the IPv6 address of the segment) is moved into the + DA of the packet. + + The DA of the packet changes at each segment termination/completion + and therefore the final DA of the packet MUST be encoded as the last + segment of the path. + +4. SRH Procedures + + In this section we describe the different procedures on the SRH. + +4.1. Source SR Node + + A Source SR Node can be any node originating an IPv6 packet with its + IPv6 and Segment Routing Headers. This include either: + + A host originating an IPv6 packet. + + An SR domain ingress router encapsulating a received IPv6 packet + into an outer IPv6 header followed by an SRH. + + + + +Previdi, et al. Expires August 5, 2017 [Page 14] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + The mechanism through which a Segment List is derived is outside of + the scope of this document. As an example, the Segment List may be + obtained through: + + Local path computation. + + Local configuration. + + Interaction with a centralized controller delivering the path. + + Any other mechanism. + + The following are the steps of the creation of the SRH: + + Next Header and Hdr Ext Len fields are set according to [RFC2460]. + + Routing Type field is set as TBD (to be allocated by IANA, + suggested value 4). + + The Segment List is built with the FIRST segment of the path + encoded in the LAST element of the Segment List. Subsequent + segments are encoded on top of the first segment. Finally, the + LAST segment of the path is encoded in the FIRST element of the + Segment List. In other words, the Segment List is encoded in the + reverse order of the path. + + The final DA of the packet is encoded as the last segment of the + path (encoded in the first element of the Segment List). + + The DA of the packet is set with the value of the first segment + (found in the last element of the segment list). + + The Segments Left field is set to n-1 where n is the number of + elements in the Segment List. + + The First Segment field is set to n-1 where n is the number of + elements in the Segment List. + + The packet is sent out towards the first segment (i.e.: + represented in the packet DA). + + HMAC TLV may be set according to Section 5. + +4.2. Transit Node + + According to [RFC2460], the only node who is allowed to inspect the + Routing Extension Header (and therefore the SRH), is the node + corresponding to the DA of the packet. Any other transit node MUST + + + +Previdi, et al. Expires August 5, 2017 [Page 15] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + NOT inspect the underneath routing header and MUST forward the packet + towards the DA and according to the IPv6 routing table. + + In the example case described in Section 2.2.2, when SR capable nodes + are connected through an overlay spanning multiple third-party + infrastructure, it is safe to send SRH packets (i.e.: packet having a + Segment Routing Header) between each other overlay/SR-capable nodes + as long as the segment list does not include any of the transit + provider nodes. In addition, as a generic security measure, any + service provider will block any packet destined to one of its + internal routers, especially if these packets have an extended header + in it. + +4.3. SR Segment Endpoint Node + + The SR segment endpoint node is the node whose address is in the DA. + The segment endpoint node inspects the SRH and does: + + 1. IF DA = myself (segment endpoint) + 2. IF Segments Left > 0 THEN + decrement Segments Left + update DA with Segment List[Segments Left] + 3. ELSE continue IPv6 processing of the packet + End of processing. + 4. Forward the packet out + +5. Security Considerations + + This section analyzes the security threat model, the security issues + and proposed solutions related to the new Segment Routing Header. + + The Segment Routing Header (SRH) is simply another type of the + routing header as described in RFC 2460 [RFC2460] and is: + + o Added by an SR edge router when entering the segment routing + domain or by the originating host itself. The source host can + even be outside the SR domain; + + o inspected and acted upon when reaching the destination address of + the IP header per RFC 2460 [RFC2460]. + + Per RFC2460 [RFC2460], routers on the path that simply forward an + IPv6 packet (i.e. the IPv6 destination address is none of theirs) + will never inspect and process the content of the SRH. Routers whose + one interface IPv6 address equals the destination address field of + the IPv6 packet MUST parse the SRH and, if supported and if the local + configuration allows it, MUST act accordingly to the SRH content. + + + + +Previdi, et al. Expires August 5, 2017 [Page 16] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + According to RFC2460 [RFC2460], the default behavior of a non SR- + capable router upon receipt of an IPv6 packet with SRH destined to an + address of its, is to: + + o ignore the SRH completely if the Segment Left field is 0 and + proceed to process the next header in the IPv6 packet; + + o discard the IPv6 packet if Segment Left field is greater than 0, + it MAY send a Parameter Problem ICMP message back to the Source + Address. + +5.1. Threat model + +5.1.1. Source routing threats + + Using an SRH is similar to source routing, therefore it has some + well-known security issues as described in RFC4942 [RFC4942] section + 2.1.1 and RFC5095 [RFC5095]: + + o amplification attacks: where a packet could be forged in such a + way to cause looping among a set of SR-enabled routers causing + unnecessary traffic, hence a Denial of Service (DoS) against + bandwidth; + + o reflection attack: where a hacker could force an intermediate node + to appear as the immediate attacker, hence hiding the real + attacker from naive forensic; + + o bypass attack: where an intermediate node could be used as a + stepping stone (for example in a De-Militarized Zone) to attack + another host (for example in the datacenter or any back-end + server). + +5.1.2. Applicability of RFC 5095 to SRH + + First of all, the reader must remember this specific part of section + 1 of RFC5095 [RFC5095], "A side effect is that this also eliminates + benign RH0 use-cases; however, such applications may be facilitated + by future Routing Header specifications.". In short, it is not + forbidden to create new secure type of Routing Header; for example, + RFC 6554 (RPL) [RFC6554] also creates a new Routing Header type for a + specific application confined in a single network. + + In the segment routing architecture described in + [I-D.ietf-spring-segment-routing] there are basically two kinds of + nodes (routers and hosts): + + + + + +Previdi, et al. Expires August 5, 2017 [Page 17] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + o nodes within the SR domain, which is within one single + administrative domain, i.e., where all nodes are trusted anyway + else the damage caused by those nodes could be worse than + amplification attacks: traffic interception, man-in-the-middle + attacks, more server DoS by dropping packets, and so on. + + o nodes outside of the SR domain, which is outside of the + administrative segment routing domain hence they cannot be trusted + because there is no physical security for those nodes, i.e., they + can be replaced by hostile nodes or can be coerced in wrong + behaviors. + + The main use case for SR consists of the single administrative domain + where only trusted nodes with SR enabled and configured participate + in SR: this is the same model as in RFC6554 [RFC6554]. All non- + trusted nodes do not participate as either SR processing is not + enabled by default or because they only process SRH from nodes within + their domain. + + Moreover, all SR nodes ignore SRH created by outsiders based on + topology information (received on a peering or internal interface) or + on presence and validity of the HMAC field. Therefore, if + intermediate nodes ONLY act on valid and authorized SRH (such as + within a single administrative domain), then there is no security + threat similar to RH-0. Hence, the RFC 5095 [RFC5095] attacks are + not applicable. + +5.1.3. Service stealing threat + + Segment routing is used for added value services, there is also a + need to prevent non-participating nodes to use those services; this + is called 'service stealing prevention'. + +5.1.4. Topology disclosure + + The SRH may also contains IPv6 addresses of some intermediate SR- + nodes in the path towards the destination, this obviously reveals + those addresses to the potentially hostile attackers if those + attackers are able to intercept packets containing SRH. On the other + hand, if the attacker can do a traceroute whose probes will be + forwarded along the SR path, then there is little learned by + intercepting the SRH itself. + +5.1.5. ICMP Generation + + Per section 4.4 of RFC2460 [RFC2460], when destination nodes (i.e. + where the destination address is one of theirs) receive a Routing + Header with unsupported Routing Type, the required behavior is: + + + +Previdi, et al. Expires August 5, 2017 [Page 18] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + o If Segments Left is zero, the node must ignore the Routing header + and proceed to process the next header in the packet. + + o If Segments Left is non-zero, the node must discard the packet and + send an ICMP Parameter Problem, Code 0, message to the packet's + Source Address, pointing to the unrecognized Routing Type. + + This required behavior could be used by an attacker to force the + generation of ICMP message by any node. The attacker could send + packets with SRH (with Segment Left set to 0) destined to a node not + supporting SRH. Per RFC2460 [RFC2460], the destination node could + generate an ICMP message, causing a local CPU utilization and if the + source of the offending packet with SRH was spoofed could lead to a + reflection attack without any amplification. + + It must be noted that this is a required behavior for any unsupported + Routing Type and not limited to SRH packets. So, it is not specific + to SRH and the usual rate limiting for ICMP generation is required + anyway for any IPv6 implementation and has been implemented and + deployed for many years. + +5.2. Security fields in SRH + + This section summarizes the use of specific fields in the SRH. They + are based on a key-hashed message authentication code (HMAC). + + The security-related fields in the SRH are instantiated by the HMAC + TLV, containing: + + o HMAC Key-id, 32 bits wide; + + o HMAC, 256 bits wide (optional, exists only if HMAC Key-id is not + 0). + + The HMAC field is the output of the HMAC computation (per RFC 2104 + [RFC2104]) using a pre-shared key identified by HMAC Key-id and of + the text which consists of the concatenation of: + + o the source IPv6 address; + + o First Segment field; + + o an octet of bit flags; + + o HMAC Key-id; + + o all addresses in the Segment List. + + + + +Previdi, et al. Expires August 5, 2017 [Page 19] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + The purpose of the HMAC TLV is to verify the validity, the integrity + and the authorization of the SRH itself. If an outsider of the SR + domain does not have access to a current pre-shared secret, then it + cannot compute the right HMAC field and the first SR router on the + path processing the SRH and configured to check the validity of the + HMAC will simply reject the packet. + + The HMAC TLV is located at the end of the SRH simply because only the + router on the ingress of the SR domain needs to process it, then all + other SR nodes can ignore it (based on local policy) because they + trust the upstream router. This is to speed up forwarding operations + because SR routers which do not validate the SRH do not need to parse + the SRH until the end. + + The HMAC Key-id field allows for the simultaneous existence of + several hash algorithms (SHA-256, SHA3-256 ... or future ones) as + well as pre-shared keys. The HMAC Key-id field is opaque, i.e., it + has neither syntax nor semantic except as an index to the right + combination of pre-shared key and hash algorithm and except that a + value of 0 means that there is no HMAC field. Having an HMAC Key-id + field allows for pre-shared key roll-over when two pre-shared keys + are supported for a while when all SR nodes converged to a fresher + pre-shared key. It could also allow for interoperation among + different SR domains if allowed by local policy and assuming a + collision-free HMAC Key Id allocation. + + When a specific SRH is linked to a time-related service (such as + turbo-QoS for a 1-hour period) where the DA, Segment ID (SID) are + identical, then it is important to refresh the shared-secret + frequently as the HMAC validity period expires only when the HMAC + Key-id and its associated shared-secret expires. + +5.2.1. Selecting a hash algorithm + + The HMAC field in the HMAC TLV is 256 bit wide. Therefore, the HMAC + MUST be based on a hash function whose output is at least 256 bits. + If the output of the hash function is 256, then this output is simply + inserted in the HMAC field. If the output of the hash function is + larger than 256 bits, then the output value is truncated to 256 by + taking the least-significant 256 bits and inserting them in the HMAC + field. + + SRH implementations can support multiple hash functions but MUST + implement SHA-2 [FIPS180-4] in its SHA-256 variant. + + NOTE: SHA-1 is currently used by some early implementations used for + quick interoperations testing, the 160-bit hash value must then be + + + + +Previdi, et al. Expires August 5, 2017 [Page 20] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + right-hand padded with 96 bits set to 0. The authors understand that + this is not secure but is ok for limited tests. + +5.2.2. Performance impact of HMAC + + While adding an HMAC to each and every SR packet increases the + security, it has a performance impact. Nevertheless, it must be + noted that: + + o the HMAC field is used only when SRH is added by a device (such as + a home set-up box) which is outside of the segment routing domain. + If the SRH is added by a router in the trusted segment routing + domain, then, there is no need for an HMAC field, hence no + performance impact. + + o when present, the HMAC field MUST only be checked and validated by + the first router of the segment routing domain, this router is + named 'validating SR router'. Downstream routers may not inspect + the HMAC field. + + o this validating router can also have a cache of <IPv6 header + + SRH, HMAC field value> to improve the performance. It is not the + same use case as in IPsec where HMAC value was unique per packet, + in SRH, the HMAC value is unique per flow. + + o Last point, hash functions such as SHA-2 have been optimized for + security and performance and there are multiple implementations + with good performance. + + With the above points in mind, the performance impact of using HMAC + is minimized. + +5.2.3. Pre-shared key management + + The field HMAC Key-id allows for: + + o key roll-over: when there is a need to change the key (the hash + pre-shared secret), then multiple pre-shared keys can be used + simultaneously. The validating routing can have a table of <HMAC + Key-id, pre-shared secret> for the currently active and future + keys. + + o different algorithms: by extending the previous table to <HMAC + Key-id, hash function, pre-shared secret>, the validating router + can also support simultaneously several hash algorithms (see + section Section 5.2.1) + + The pre-shared secret distribution can be done: + + + +Previdi, et al. Expires August 5, 2017 [Page 21] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + o in the configuration of the validating routers, either by static + configuration or any SDN oriented approach; + + o dynamically using a trusted key distribution such as [RFC6407] + + The intent of this document is NOT to define yet-another-key- + distribution-protocol. + +5.3. Deployment Models + +5.3.1. Nodes within the SR domain + + An SR domain is defined as a set of interconnected routers where all + routers at the perimeter are configured to add and act on SRH. Some + routers inside the SR domain can also act on SRH or simply forward + IPv6 packets. + + The routers inside an SR domain can be trusted to generate SRH and to + process SRH received on interfaces that are part of the SR domain. + These nodes MUST drop all SRH packets received on an interface that + is not part of the SR domain and containing an SRH whose HMAC field + cannot be validated by local policies. This includes obviously + packet with an SRH generated by a non-cooperative SR domain. + + If the validation fails, then these packets MUST be dropped, ICMP + error messages (parameter problem) SHOULD be generated (but rate + limited) and SHOULD be logged. + +5.3.2. Nodes outside of the SR domain + + Nodes outside of the SR domain cannot be trusted for physical + security; hence, they need to request by some trusted means (outside + of the scope of this document) a complete SRH for each new connection + (i.e. new destination address). The received SRH MUST include an + HMAC TLV which is computed correctly (see Section 5.2). + + When an outside node sends a packet with an SRH and towards an SR + domain ingress node, the packet MUST contain the HMAC TLV (with a + Key-id and HMAC fields) and the the destination address MUST be an + address of an SR domain ingress node . + + The ingress SR router, i.e., the router with an interface address + equals to the destination address, MUST verify the HMAC TLV. + + If the validation is successful, then the packet is simply forwarded + as usual for an SR packet. As long as the packet travels within the + SR domain, no further HMAC check needs to be done. Subsequent + + + + +Previdi, et al. Expires August 5, 2017 [Page 22] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + routers in the SR domain MAY verify the HMAC TLV when they process + the SRH (i.e. when they are the destination). + + If the validation fails, then this packet MUST be dropped, an ICMP + error message (parameter problem) SHOULD be generated (but rate + limited) and SHOULD be logged. + +5.3.3. SR path exposure + + As the intermediate SR nodes addresses appears in the SRH, if this + SRH is visible to an outsider then he/she could reuse this knowledge + to launch an attack on the intermediate SR nodes or get some insider + knowledge on the topology. This is especially applicable when the + path between the source node and the first SR domain ingress router + is on the public Internet. + + The first remark is to state that 'security by obscurity' is never + enough; in other words, the security policy of the SR domain MUST + assume that the internal topology and addressing is known by the + attacker. A simple traceroute will also give the same information + (with even more information as all intermediate nodes between SID + will also be exposed). IPsec Encapsulating Security Payload + [RFC4303] cannot be use to protect the SRH as per RFC4303 the ESP + header must appear after any routing header (including SRH). + + To prevent a user to leverage the gained knowledge by intercepting + SRH, it it recommended to apply an infrastructure Access Control List + (iACL) at the edge of the SR domain. This iACL will drop all packets + from outside the SR-domain whose destination is any address of any + router inside the domain. This security policy should be tuned for + local operations. + +5.3.4. Impact of BCP-38 + + BCP-38 [RFC2827], also known as "Network Ingress Filtering", checks + whether the source address of packets received on an interface is + valid for this interface. The use of loose source routing such as + SRH forces packets to follow a path which differs from the expected + routing. Therefore, if BCP-38 was implemented in all routers inside + the SR domain, then SR packets could be received by an interface + which is not expected one and the packets could be dropped. + + As an SR domain is usually a subset of one administrative domain, and + as BCP-38 is only deployed at the ingress routers of this + administrative domain and as packets arriving at those ingress + routers have been normally forwarded using the normal routing + information, then there is no reason why this ingress router should + + + + +Previdi, et al. Expires August 5, 2017 [Page 23] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + drop the SRH packet based on BCP-38. Routers inside the domain + commonly do not apply BCP-38; so, this is not a problem. + +6. IANA Considerations + + This document makes the following registrations in the Internet + Protocol Version 6 (IPv6) Parameters "Routing Type" registry + maintained by IANA: + + Suggested Description Reference + Value + ---------------------------------------------------------- + 4 Segment Routing Header (SRH) This document + + In addition, this document request IANA to create and maintain a new + Registry: "Segment Routing Header Type-Value Objects". The following + code-points are requested from the registry: + + Registry: Segment Routing Header Type-Value Objects + + Suggested Description Reference + Value + ----------------------------------------------------- + 1 Ingress Node TLV This document + 2 Egress Node TLV This document + 3 Opaque Container TLV This document + 4 Padding TLV This document + 5 HMAC TLV This document + +7. Manageability Considerations + + TBD + +8. Contributors + + Dave Barach, John Leddy, John Brzozowski, Pierre Francois, Nagendra + Kumar, Mark Townsley, Christian Martin, Roberta Maglione, James + Connolly, Aloys Augustin contributed to the content of this document. + +9. Acknowledgements + + The authors would like to thank Ole Troan, Bob Hinden, Fred Baker, + Brian Carpenter, Alexandru Petrescu and Punit Kumar Jaiswal for their + comments to this document. + + + + + + + +Previdi, et al. Expires August 5, 2017 [Page 24] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + +10. References + +10.1. Normative References + + [FIPS180-4] + National Institute of Standards and Technology, "FIPS + 180-4 Secure Hash Standard (SHS)", March 2012, + <http://csrc.nist.gov/publications/fips/fips180-4/ + fips-180-4.pdf>. + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, + DOI 10.17487/RFC2119, March 1997, + <http://www.rfc-editor.org/info/rfc2119>. + + [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 + (IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460, + December 1998, <http://www.rfc-editor.org/info/rfc2460>. + + [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", + RFC 4303, DOI 10.17487/RFC4303, December 2005, + <http://www.rfc-editor.org/info/rfc4303>. + + [RFC5095] Abley, J., Savola, P., and G. Neville-Neil, "Deprecation + of Type 0 Routing Headers in IPv6", RFC 5095, + DOI 10.17487/RFC5095, December 2007, + <http://www.rfc-editor.org/info/rfc5095>. + + [RFC6407] Weis, B., Rowles, S., and T. Hardjono, "The Group Domain + of Interpretation", RFC 6407, DOI 10.17487/RFC6407, + October 2011, <http://www.rfc-editor.org/info/rfc6407>. + +10.2. Informative References + + [I-D.ietf-isis-segment-routing-extensions] + Previdi, S., Filsfils, C., Bashandy, A., Gredler, H., + Litkowski, S., Decraene, B., and j. jefftant@gmail.com, + "IS-IS Extensions for Segment Routing", draft-ietf-isis- + segment-routing-extensions-09 (work in progress), October + 2016. + + [I-D.ietf-ospf-ospfv3-segment-routing-extensions] + Psenak, P., Previdi, S., Filsfils, C., Gredler, H., + Shakir, R., Henderickx, W., and J. Tantsura, "OSPFv3 + Extensions for Segment Routing", draft-ietf-ospf-ospfv3- + segment-routing-extensions-07 (work in progress), October + 2016. + + + + +Previdi, et al. Expires August 5, 2017 [Page 25] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + [I-D.ietf-spring-ipv6-use-cases] + Brzozowski, J., Leddy, J., Townsley, W., Filsfils, C., and + R. Maglione, "IPv6 SPRING Use Cases", draft-ietf-spring- + ipv6-use-cases-08 (work in progress), January 2017. + + [I-D.ietf-spring-resiliency-use-cases] + Filsfils, C., Previdi, S., Decraene, B., and R. Shakir, + "Resiliency use cases in SPRING networks", draft-ietf- + spring-resiliency-use-cases-08 (work in progress), October + 2016. + + [I-D.ietf-spring-segment-routing] + Filsfils, C., Previdi, S., Decraene, B., Litkowski, S., + and R. Shakir, "Segment Routing Architecture", draft-ietf- + spring-segment-routing-10 (work in progress), November + 2016. + + [I-D.ietf-spring-segment-routing-mpls] + Filsfils, C., Previdi, S., Bashandy, A., Decraene, B., + Litkowski, S., Horneffer, M., Shakir, R., + jefftant@gmail.com, j., and E. Crabbe, "Segment Routing + with MPLS data plane", draft-ietf-spring-segment-routing- + mpls-06 (work in progress), January 2017. + + [RFC1940] Estrin, D., Li, T., Rekhter, Y., Varadhan, K., and D. + Zappala, "Source Demand Routing: Packet Format and + Forwarding Specification (Version 1)", RFC 1940, + DOI 10.17487/RFC1940, May 1996, + <http://www.rfc-editor.org/info/rfc1940>. + + [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- + Hashing for Message Authentication", RFC 2104, + DOI 10.17487/RFC2104, February 1997, + <http://www.rfc-editor.org/info/rfc2104>. + + [RFC2827] Ferguson, P. and D. Senie, "Network Ingress Filtering: + Defeating Denial of Service Attacks which employ IP Source + Address Spoofing", BCP 38, RFC 2827, DOI 10.17487/RFC2827, + May 2000, <http://www.rfc-editor.org/info/rfc2827>. + + [RFC4942] Davies, E., Krishnan, S., and P. Savola, "IPv6 Transition/ + Co-existence Security Considerations", RFC 4942, + DOI 10.17487/RFC4942, September 2007, + <http://www.rfc-editor.org/info/rfc4942>. + + + + + + + +Previdi, et al. Expires August 5, 2017 [Page 26] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + [RFC6554] Hui, J., Vasseur, JP., Culler, D., and V. Manral, "An IPv6 + Routing Header for Source Routes with the Routing Protocol + for Low-Power and Lossy Networks (RPL)", RFC 6554, + DOI 10.17487/RFC6554, March 2012, + <http://www.rfc-editor.org/info/rfc6554>. + + [RFC7855] Previdi, S., Ed., Filsfils, C., Ed., Decraene, B., + Litkowski, S., Horneffer, M., and R. Shakir, "Source + Packet Routing in Networking (SPRING) Problem Statement + and Requirements", RFC 7855, DOI 10.17487/RFC7855, May + 2016, <http://www.rfc-editor.org/info/rfc7855>. + +Authors' Addresses + + Stefano Previdi (editor) + Cisco Systems, Inc. + Via Del Serafico, 200 + Rome 00142 + Italy + + Email: sprevidi@cisco.com + + + Clarence Filsfils + Cisco Systems, Inc. + Brussels + BE + + Email: cfilsfil@cisco.com + + + Brian Field + Comcast + 4100 East Dry Creek Road + Centennial, CO 80122 + US + + Email: Brian_Field@cable.comcast.com + + + Ida Leung + Rogers Communications + 8200 Dixie Road + Brampton, ON L6T 0C1 + CA + + Email: Ida.Leung@rci.rogers.com + + + + +Previdi, et al. Expires August 5, 2017 [Page 27] + +Internet-Draft IPv6 Segment Routing Header (SRH) February 2017 + + + Jen Linkova + Google + 1600 Amphitheatre Parkway + Mountain View, CA 94043 + US + + Email: furry@google.com + + + Ebben Aries + Facebook + US + + Email: exa@fb.com + + + Tomoya Kosugi + NTT + 3-9-11, Midori-Cho Musashino-Shi, + Tokyo 180-8585 + JP + + Email: kosugi.tomoya@lab.ntt.co.jp + + + Eric Vyncke + Cisco Systems, Inc. + De Kleetlaann 6A + Diegem 1831 + Belgium + + Email: evyncke@cisco.com + + + David Lebrun + Universite Catholique de Louvain + Place Ste Barbe, 2 + Louvain-la-Neuve, 1348 + Belgium + + Email: david.lebrun@uclouvain.be + + + + + + + + + + +Previdi, et al. Expires August 5, 2017 [Page 28]
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