<?xmlversion="1.0" encoding="US-ASCII"?>version='1.0' encoding='utf-8'?> <!DOCTYPE rfc SYSTEM"rfc2629.dtd"> <?rfc toc="yes"?> <?rfc tocompact="yes"?> <?rfc tocdepth="3"?> <?rfc tocindent="yes"?> <?rfc symrefs="yes"?> <?rfc sortrefs="yes"?> <?rfc comments="yes"?> <?rfc inline="yes"?> <?rfc compact="yes"?> <?rfc subcompact="no"?>"rfc2629-xhtml.ent"> <rfc xmlns:xi="http://www.w3.org/2001/XInclude" category="std" docName="draft-ietf-ospf-encapsulation-cap-09"ipr="trust200902">ipr="trust200902" obsoletes="" updates="" submissionType="IETF" xml:lang="en" tocInclude="true" tocDepth="3" symRefs="true" sortRefs="true" version="3" number="9013" consensus="true"> <!-- xml2rfc v2v3 conversion 2.46.0 --> <front> <title abbrev="Tunnel EncapsulationsRI">TheRI">OSPF Advertisement of TunnelEncapsulations OSPF Router Information</title>Encapsulations</title> <seriesInfo name="RFC" value="9013"/> <author fullname="Xiaohu Xu"initials="X.X."initials="X" role="editor" surname="Xu"><organization>Huawei</organization><organization>Capitalonline</organization> <address><email>xuxiaohu@huawei.com</email><email>xiaohu.xu@capitalonline.net</email> </address> </author> <author fullname="BrunoDecraene " initials="B.D."Decraene" initials="B" role="editor" surname="Decraene"> <organization>Orange</organization> <address> <email>bruno.decraene@orange.com</email> </address> </author> <author fullname="Robert Raszuk"initials="R.R."initials="R" surname="Raszuk"><organization>Bloomberg LP</organization><organization>NTT Network Innovations</organization> <address><!--<postal><street></street> --> <!-- Reorder these if your country does things differently --> <!-- <city>Soham</city> <region></region> <code></code> <country>UK</country><street>940 Stewart Dr</street> <city>Sunnyvale</city> <region>CA</region> <code>94085</code> <country>United States of America</country> </postal><phone>+44 7889 488 335</phone> --><email>robert@raszuk.net</email><!-- uri and facsimile elements may also be added --></address> </author> <author fullname="Luis M. Contreras"initials="L.C."initials="L" surname="Contreras"> <organization>Telefonica I+D</organization> <address> <email>luismiguel.contrerasmurillo@telefonica.com</email> </address> </author> <author fullname="Luay Jalil"initials="L.J."initials="L" surname="Jalil"> <organization>Verizon</organization> <address> <email>luay.jalil@verizon.com</email> </address> </author> <dateyear='2017'/> <area>Routing Area</area> <workgroup>OSPF Working Group</workgroup>year="2021" month="April"/> <keyword>BGP</keyword> <abstract> <t>Networks use tunnels for a variety of reasons. A large variety of tunnel types aredefineddefined, and the tunnel encapsulator router needs to select a type of tunnelwhichthat is supported by the tunnel decapsulator router. This document defines how to advertise, in OSPF Router Information Link StateAdvertisementAdvertisements (LSAs), the list of tunnel encapsulations supported by the tunnel decapsulator.</t> </abstract><note title="Requirements Language"> <t>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 <xref target="RFC2119">RFC 2119</xref>.</t> </note></front> <middle> <section anchor="Introduction"title="Introduction">numbered="true" toc="default"> <name>Introduction</name> <t>Networks use tunnels for a variety of reasons, such as:</t><t><list style="symbols"> <t>Partial<ul spacing="normal"> <li>Partial deployment of IPv6 in IPv4 networks or IPv4 in IPv6networksnetworks, as described in <xreftarget="RFC5565"/>,target="RFC5565" format="default"/>, where IPvx tunnels are used between IPvx-enabled routers so as to traverse non-IPvxrouters.</t> <t>Remoterouters.</li> <li>Remote Loop-Free Alternate (RLFA) repair tunnels as described in <xreftarget="RFC7490"/>,target="RFC7490" format="default"/>, where tunnels are used between the Point of Local Repair and the selected PQnode.</t> </list></t>node.</li> </ul> <t>The tunnel encapsulator router needs to select a type of tunnelwhichthat is supported by the tunnel decapsulator router. This document defines how to advertise, in OSPF Router Information Link StateAdvertisementAdvertisements (LSAs), the list of tunnel encapsulations supported by the tunnel decapsulator. In this document, OSPF refers to both OSPFv2 <xreftarget="RFC2328"/>target="RFC2328" format="default"/> and OSPFv3 <xreftarget="RFC5340"/>.</t>target="RFC5340" format="default"/>.</t> </section> <section anchor="Terminology"title="Terminology">numbered="true" toc="default"> <name>Terminology</name> <t>This memo makes use of the terms defined in <xreftarget="RFC7770"/>.</t>target="RFC7770" format="default"/>.</t> <t> The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>", "<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as described in BCP 14 <xref target="RFC2119"/> <xref target="RFC8174"/> when, and only when, they appear in all capitals, as shown here. </t> </section> <section anchor="RI"title="Tunnelnumbered="true" toc="default"> <name>Tunnel EncapsulationsTLV">TLV</name> <t>Routers advertise their supported tunnel encapsulation type(s) by advertising a new TLV of the OSPF Router Information (RI) Opaque LSA <xreftarget="RFC7770"/>,target="RFC7770" format="default"/>, referred to as theTunnel"Tunnel EncapsulationsTLV.TLV". This TLV is applicable to both OSPFv2 and OSPFv3.</t> <t>The Type code of the Tunnel Encapsulations TLV isTBD1,13, the Length value is variable, and the Value field contains one or more TunnelSub-TLVsSub-TLVs, as defined in <xreftarget="TunnelType"/>.target="TunnelType" format="default"/>. Each Tunnel Sub-TLV indicates a particular encapsulation format that the advertising routersupportssupports, along with the parameters corresponding to the tunnel type.</t> <t>The Tunnel Encapsulations TLVMAY<bcp14>MAY</bcp14> appear more than once within a given OSPF Router Information (RI) Opaque LSA. If the Tunnel Encapsulations TLV appears more than once in an OSPF Router Information LSA, the set of all Tunnel Sub-TLVs from all Tunnel EncapsulationsTLV SHOULDTLVs <bcp14>SHOULD</bcp14> be considered. The scope of the advertisement depends on theapplicationapplication, but it is recommended that itSHOULD<bcp14>SHOULD</bcp14> bedomain-wide.</t>domain wide.</t> </section> <section anchor="TunnelType"title="Tunnel Sub-TLV">numbered="true" toc="default"> <name>Tunnel Sub-TLV</name> <t>The Tunnel Sub-TLV is structured asfollows:</t> <t><figure anchor="Tunnel_Sub-TLV" title="Tunnel Sub-TLV"> <artwork><![CDATA[shown in <xref target="Tunnel_Sub-TLV"/>.</t> <figure anchor="Tunnel_Sub-TLV"> <name>Tunnel Sub-TLV</name> <artwork name="" type="" align="left" alt=""><![CDATA[ 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Tunnel Type (2Octets)octets) | Length (2Octets)octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | Tunnel Parameter Sub-TLVs | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+]]></artwork> </figure></t> <t><list> <t>Tunnel]]></artwork></figure> <dl newline="false"> <dt>Tunnel Type (2octets): Identifiesoctets):</dt><dd>Identifies the type of tunneling technology signaled. Tunnel types are shared with the BGP extension <xreftarget="I-D.ietf-idr-tunnel-encaps"/>target="RFC9012" format="default"/> and hence are defined in the IANA registry "BGP Tunnel Encapsulation Attribute Tunnel Types". UnknownTunneltunnel types are to be ignored uponreceipt.</t> <t>Lengthreceipt.</dd> <dt>Length (2octets): Unsignedoctets):</dt><dd>Unsigned 16-bit integer indicating the total number of octets of thevalue field.</t> <t>Value (variable): ZeroTunnel Parameter Sub-TLVs field.</dd> <dt>Tunnel Parameter Sub-TLVs (variable):</dt><dd>Zero or more Tunnel ParameterSub-TLVsSub-TLVs, as defined in <xreftarget="ParameterTLVs"/>.</t> </list></t>target="ParameterTLVs" format="default"/>.</dd> </dl> <t>If a Tunnel Sub-TLV is invalid, itMUST<bcp14>MUST</bcp14> be ignored and skipped. However, other Tunnel Sub-TLVsMUST<bcp14>MUST</bcp14> beconsidered</t>considered.</t> </section> <section anchor="ParameterTLVs"title="Tunnelnumbered="true" toc="default"> <name>Tunnel ParameterSub-TLVs">Sub-TLVs</name> <t>A Tunnel Parameter Sub-TLV is structured asfollows:</t> <t><figure anchor="Tunnel_Parameter_Sub-TLV" title="Tunnelshown in <xref target="Tunnel_Parameter_Sub-TLV"/>.</t> <figure anchor="Tunnel_Parameter_Sub-TLV"> <name>Tunnel ParameterSub-TLV"> <artwork><![CDATA[Sub-TLV</name> <artwork name="" type="" align="left" alt=""><![CDATA[ +---------------------------------------------+ | Tunnel Parameter Sub-Type (2Octets)octets) | +---------------------------------------------+ | Tunnel Parameter Length (2Octets)octets) | +---------------------------------------------+ | Tunnel Parameter Value(Variable)(variable) | | | +---------------------------------------------+]]></artwork> </figure><list> <t>Tunnel]]></artwork></figure> <dl newline="false"> <dt>Tunnel Parameter Sub-Type (2octets): Eachoctets):</dt><dd>Each sub-type defines a parameter of the Tunnel Sub-TLV.Sub-TypesSub-types are registered in the IANA registry "OSPF Tunnel Parameter Sub-TLVs" (see <xreftarget="ParameterRegistry"/>.</t> <t>Tunneltarget="ParameterRegistry" format="default"/>).</dd> <dt>Tunnel Parameter Length (2octets): Unsignedoctets):</dt><dd>Unsigned 16-bit integer indicating the total number of octets of the Tunnel Parameter Valuefield.</t> <t>Tunnelfield.</dd> <dt>Tunnel Parameter Value(variable): Encodings(variable):</dt><dd>Encodings of thevalueValue field depend on theSub-TLV type as enumerated above.sub-TLV type. The followingsub-sectionssubsections define the encoding indetail.</t> </list>Anydetail.</dd> </dl> <t>Any unknown Tunnel ParameterSub-Type MUSTsub-type <bcp14>MUST</bcp14> be ignored and skipped upon receipt. When a reserved value(See(see <xreftarget="ParameterRegistry"/>)target="ParameterRegistry" format="default"/>) is seen in an LSA, itMUST<bcp14>MUST</bcp14> be treated as an invalid Tunnel Parameter Sub-TLV. When a Tunnel Parameter Value has an incorrect syntax orsemantic,semantics, itMUST<bcp14>MUST</bcp14> be treated as an invalid Tunnel Parameter Sub-TLV. If a Tunnel Parameter Sub-TLV is invalid, its Tunnel Sub-TLVMUST<bcp14>MUST</bcp14> be ignored. However, other Tunnel Sub-TLVsMUST<bcp14>MUST</bcp14> be considered.</t> <section anchor="EncapsulationTLV"title="Encapsulation Sub-TLV">numbered="true" toc="default"> <name>Encapsulation Sub-TLV</name> <t>ThisSub-TLVsub-TLV type is 1. The syntax,semantic,semantics, and usage of itsvalueValue field are defined in Section3.2 "Encapsulation<xref target="RFC9012" sectionFormat="bare" section="3.2">"Encapsulation Sub-TLVs for Particular TunnelTypes"Types"</xref> of <xreftarget="I-D.ietf-idr-tunnel-encaps"/>.</t>target="RFC9012" format="default"/>.</t> </section> <section anchor="ProtocolTLV"title="Protocolnumbered="true" toc="default"> <name>Protocol TypeSub-TLV">Sub-TLV</name> <t>ThisSub-TLVsub-TLV type is 2. The syntax,semantic,semantics, and usage of itsvalueValue field are defined in Section3.4.1 "Protocol<xref target="RFC9012" sectionFormat="bare" section="3.4.1">"Protocol Typesub-TLV"Sub-TLV"</xref> of <xreftarget="I-D.ietf-idr-tunnel-encaps"/>.</t>target="RFC9012" format="default"/>.</t> </section> <section anchor="EndpointTLV"title="Endpoint Sub-TLV"> <t>Thisnumbered="true" toc="default"> <name>Tunnel Egress Endpoint Sub-TLV</name> <t>The Tunnel Egress Endpoint Sub-TLV specifies the address of the egress endpoint of the tunnel -- that is, the address of the router that will decapsulate the payload.</t> <t>This sub-TLV type is 3. ItMUST<bcp14>MUST</bcp14> be present once and only once in a given Tunnel Sub-TLV. ThevalueValue fieldcontaincontains twosub-fields: <list> <t>asubfields: </t> <ul spacing="normal"> <li>a two-octet Address Familysub-field</t> <t>ansubfield</li> <li>an Addresssub-field,subfield, whose length depends upon the AddressFamily.</t> </list></t> <t><figure anchor="Endpoint_Sub-TLV" title="Endpoint Sub-TLV"> <artwork><![CDATA[Family</li> </ul> <figure anchor="Endpoint_Sub-TLV"> <name>Tunnel Egress Endpoint Sub-TLV</name> <artwork name="" type="" align="left" alt=""><![CDATA[ 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Address Family | Address ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + ~(Variable(variable length) ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ]]></artwork></figure></t></figure> <t>The Address Family subfield contains a value from IANA's "Address Family Numbers" registry. In this document, we assume that the Address Family is either IPv4 or IPv6; use of other address families is outside the scope of this document.</t> <t>If the Address Family subfield contains the value for IPv4, theaddressAddress subfieldMUST<bcp14>MUST</bcp14> contain an IPv4 address (a /32 IPv4 prefix). In this case, thelengthLength field ofRemotethe Tunnel Egress Endpointsub-TLV MUSTSub-TLV <bcp14>MUST</bcp14> contain the value 6.</t> <t>If the Address Family subfield contains the value for IPv6, the addresssub-field MUSTsubfield <bcp14>MUST</bcp14> contain an IPv6 address (a /128 IPv6 prefix). In this case, thelengthLength field ofRemotethe Tunnel Egress Endpointsub-TLV MUSTSub-TLV <bcp14>MUST</bcp14> contain the value 18 (0x12). IPv6link locallink-local addresses are not valid values of the IP address field.</t> </section> <section anchor="ColorTLV"title="Color Sub-TLV">numbered="true" toc="default"> <name>Color Sub-TLV</name> <t>ThisSub-TLVsub-TLV type is 4. It may appear zero or moretimetimes in a given Tunnel Sub-TLV. ThevalueValue field is a 4-octet opaque unsigned integer.</t> <t>The color value is user-defined and configured locally on the advertising routers. It may be used by service providers to define policies on the tunnel encapsulator routers, for example, to control the selection of the tunnel to use.</t> <t>This color value can be referenced by BGP routes carrying the Color Extended Community <xreftarget="I-D.ietf-idr-tunnel-encaps"/>.target="RFC9012" format="default"/>. If the tunnel is used to reach the BGPNext-Hopnext hop of BGP routes, then attaching a Color Extended Community to those routesexpressexpresses the willingness of the BGP speaker to use a tunnel of the same color.</t> </section> <section anchor="Load-Balancing"title="Load-Balancingnumbered="true" toc="default"> <name>Load-Balancing BlockSub-TLV">Sub-TLV</name> <t>ThisSub-TLVsub-TLV type is 5. The syntax,semantic,semantics, and usage of itsvalueValue field are defined in <xreftarget="RFC5640"/>.</t>target="RFC5640" format="default"/>.</t> </section> <section anchor="IP.QoS"title="IP QoS Field">numbered="true" toc="default"> <name>DS Field Sub-TLV</name> <t>ThisSub-TLVsub-TLV type is 6. The syntax,semantic,semantics, and usage of itsvalueValue field are defined in Section3.3.1 "IPv4 DS Field"<xref target="RFC9012" sectionFormat="bare" section="3.3.1">"DS Field"</xref> of <xreftarget="I-D.ietf-idr-tunnel-encaps"/>.</t>target="RFC9012" format="default"/>.</t> </section> <section anchor="UDP"title="UDPnumbered="true" toc="default"> <name>UDP DestinationPort">Port Sub-TLV</name> <t>ThisSub-TLVsub-TLV type is 7. The syntax,semantic,semantics, and usage of itsvalueValue field are defined in Section3.3.2 "UDP<xref target="RFC9012" sectionFormat="bare" section="3.3.2">"UDP DestinationPort"Port"</xref> of <xreftarget="I-D.ietf-idr-tunnel-encaps"/>.</t>target="RFC9012" format="default"/>.</t> </section> </section> <section anchor="Operation"title="Operation">numbered="true" toc="default"> <name>Operation</name> <t>The advertisement of a Tunnel Encapsulations Sub-TLV indicates that the advertising router supports a particular tunnel decapsulation along with the parameters to be used for the tunnel. The decision to use that tunnel is driven by the capability of the tunnel encapsulator router to support the encapsulation type and the policy on the tunnel encapsulator router. The Color Sub-TLV(See(see <xreftarget="ColorTLV"/>)target="ColorTLV" format="default"/>) may be used as an input to this policy. Note that some tunnel types may require the execution of an explicit tunnel setup protocol before they can be used to transit data.</t> <t> A tunnelMUST NOT<bcp14>MUST NOT</bcp14> be used if there is no route toward the IP address specified in the Tunnel Egress Endpoint Sub-TLV(See(see <xreftarget="EndpointTLV"/>)target="EndpointTLV" format="default"/>) or if the route is not advertised in the same OSPF domain.</t> </section> <section anchor="IANA"title="IANA Considerations">numbered="true" toc="default"> <name>IANA Considerations</name> <section anchor="IANA.RI"title="OSPFnumbered="true" toc="default"> <name>OSPF RouterInformation"> <t>This document requests IANA to allocate aInformation (RI) TLVs Registry</name> <t>IANA has allocated the following new code pointfromin theOSPF"OSPF Router Information (RI) TLVs" registry.<figure anchor="Tunnel_Encapsulation_RI" title="Tunnel Encapsulation Router Information"> <artwork><![CDATA[ Value TLV Name Reference ----- ---------------------- ------------- TBD1 Tunnel Encapsulations This document]]></artwork> </figure></t> <table anchor="encaps-router"> <name>Addition to OSPF Router Information (RI) TLVs Registry</name> <thead> <tr> <th>Value</th> <th>TLV Name</th> <th>Reference</th> </tr> </thead> <tbody> <tr> <td>13</td> <td>Tunnel Encapsulations</td> <td>RFC 9013</td> </tr> </tbody> </table> </section> <section anchor="ParameterRegistry"title="Tunnelnumbered="true" toc="default"> <name>OSPF Tunnel Parameter Sub-TLVsRegistry"> <t>This document requests IANA to create, under "Open Shortest Path First (OSPF) Parameters",Registry</name> <t>IANA has created a newregistrysubregistry called the "OSPF Tunnel Parameter Sub-TLVs"withregistry under thefollowing"Open Shortest Path First (OSPF) Parameters" registry. The registrationprocedure:<list> <t>Theprocedures are as follows:</t> <ul spacing="normal"> <li>The values in the range 1-34999 are to be allocated using the "Standards Action" registration procedureasdefined in <xreftarget="RFC8126"/>.</t> <t>Thetarget="RFC8126" format="default"/>.</li> <li>The values in the range 35000-65499 are to be allocated using the "FirstCome,Come First Served" registrationprocedure.</t> </list></t> <figure anchor="OSPF_Tunnel_Parameter_Registry" title="OSPF Tunnel Parameter Sub-TLVs Registry"> <artwork><![CDATA[ Registry Name:procedure.</li> </ul> <t>The initial contents of the registry are as follows:</t> <table anchor="sub-TLV-reg"> <name>Initial Contents of OSPF Tunnel Parameter Sub-TLVsValue Name Reference ----------- -------------------- ------------------------------ 0 Reserved This document 1 Encapsulation This document & [I-D.ietf-idr-tunnel-encaps] 2 Protocol Type This document & [I-D.ietf-idr-tunnel-encaps] 3 Endpoint This document 4 Color This document 5 Load-Balancing Block This document & [RFC5640] 6 IP QoS This document & [I-D.ietf-idr-tunnel-encaps] 7 UDPRegistry</name> <thead> <tr> <th>Value</th> <th>TLV Name</th> <th>Reference</th> </tr> </thead> <tbody> <tr> <td>0</td> <td>Reserved</td> <td>RFC 9013</td> </tr> <tr> <td>1</td> <td>Encapsulation</td> <td>RFC 9013 & RFC 9012</td> </tr> <tr> <td>2</td> <td>Protocol Type</td> <td>RFC 9013 & RFC 9012</td> </tr> <tr> <td>3</td> <td>Endpoint</td> <td>RFC 9013</td> </tr> <tr> <td>4</td> <td>Color</td> <td>RFC 9013</td> </tr> <tr> <td>5</td> <td>Load-Balancing Block</td> <td>RFC 9013 & RFC 5640</td> </tr> <tr> <td>6</td> <td>DS Field</td> <td>RFC 9013 & RFC 9012</td> </tr> <tr> <td>7</td> <td>UDP DestinationPort This document & [I-D.ietf-idr-tunnel-encaps] 8-65499 Unassigned 65500-65534 Experimental This document 65535 Reserved This document]]></artwork> </figure>Port</td> <td>RFC 9013 & RFC 9012</td> </tr> <tr> <td>8-65499</td> <td>Unassigned</td> <td></td> </tr> <tr> <td>65500-65534</td> <td>Experimental</td> <td>RFC 9013</td> </tr> <tr> <td>65535</td> <td>Reserved</td> <td>RFC 9013</td> </tr> </tbody> </table> </section> </section> <section anchor="Security"title="Security Considerations">numbered="true" toc="default"> <name>Security Considerations</name> <t>Security considerations applicable to softwires can be found in the mesh framework <xreftarget="RFC5565"/>.target="RFC5565" format="default"/>. In general, security issues of the tunnel protocols signaled through this OSPF capability extension are inherited.</t> <t>If athird-partythird party is able to modify any of the information that is used to form encapsulation headers,tochoose a tunnel type, ortochoose a particular tunnel for a particular payload type, user data packets may end up getting misrouted,mis-delivered,misdelivered, and/or dropped. However, since an OSPF routing domain is usually a well-controlled network under a single administrative domain, the possibility of the above attack is very low.</t> <t>We note that the last paragraph of <xreftarget="Operation"/> forbidtarget="Operation" format="default"/> forbids the establishment of a tunnel toward arbitrary destinations. It prohibits a destination outside of the OSPF domain. Thisavoid thatprevents athird-party gainingthird party that has gained access to an OSPF routerbefrom being able to send the traffic to other destinations, e.g., for inspection purposes.</t> <t>Security considerations for the base OSPF protocol are covered in <xreftarget="RFC2328"/>target="RFC2328" format="default"/> and <xreftarget="RFC5340"/>.</t> </section> <section title="Contributors"> <t><figure> <artwork><![CDATA[Uma Chunduri Huawei Email: uma.chunduri@gmail.com ]]></artwork> </figure></t>target="RFC5340" format="default"/>.</t> </section> </middle> <back> <references> <name>References</name> <references> <name>Normative References</name> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.7770.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8126.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5640.xml"/> <!-- draft-ietf-idr-tunnel-encaps-15 (RFC 9012) --> <reference anchor="RFC9012" target="https://www.rfc-editor.org/info/rfc9012"> <front> <title>The BGP Tunnel Encapsulation Attribute</title> <author initials='K' surname='Patel' > <organization/> </author> <author initials='G' surname='Van de Velde' > <organization/> </author> <author initials='S' surname='Sangli' > <organization/> </author> <author initials='J' surname='Scudder' > <organization/> </author> <date month='April' year='2021'/> </front> <seriesInfo name="RFC" value="9012"/> <seriesInfo name="DOI" value="10.17487/RFC9012"/> </reference> </references> <references> <name>Informative References</name> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.2328.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5340.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5512.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5565.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.7490.xml"/> </references> </references> <section anchor="Acknowledgements"title="Acknowledgements">numbered="false" toc="default"> <name>Acknowledgements</name> <t>This document is partially inspired by <xreftarget="RFC5512"/>.</t>target="RFC5512" format="default"/>.</t> <t>The authors would like to thankGreg Mirsky, John E Drake, Carlos Pignataro and Karsten Thomann<contact fullname="Greg Mirsky"/>, <contact fullname="John E. Drake"/>, <contact fullname="Carlos Pignataro"/>, and <contact fullname="Karsten Thomann"/> for their valuable comments on this document. Special thanks should be given toAcee Lindem<contact fullname="Acee Lindem"/> for his multiple detailed reviews of this document and help. The authors would like to thankPete Resnick, Joe Touch, David Mandelberg, Sabrina Tanamal, Tim Wicinski, Amanda Baber<contact fullname="Pete Resnick"/>, <contact fullname="Joe Touch"/>, <contact fullname="David Mandelberg"/>, <contact fullname="Sabrina Tanamal"/>, <contact fullname="Tim Wicinski"/>, and <contact fullname="Amanda Baber"/> for their Last Callreviews andreviews. The authors also thankSpencer Dawkins, Mirja Kuehlewind, Ben Campbell, Benoit Claise, Alvaro Retana, Adam Roach and Suresh Krishnan<contact fullname="Spencer Dawkins"/>, <contact fullname="Mirja Kühlewind"/>, <contact fullname="Ben Campbell"/>, <contact fullname="Benoit Claise"/>, <contact fullname="Alvaro Retana"/>, <contact fullname="Adam Roach"/>, and <contact fullname="Suresh Krishnan"/> for their AD reviews.</t><!----></section></middle> <back> <references title="Normative References"> <?rfc include="reference.RFC.2119"?> <?rfc include="reference.RFC.7770"?> <?rfc include="reference.RFC.8126"?> <?rfc include="reference.RFC.5640"?> <?rfc include="reference.I-D.ietf-idr-tunnel-encaps"?> </references> <references title="Informative References"> <?rfc include="reference.RFC.2328"?> <?rfc include="reference.RFC.5340"?> <?rfc include="reference.RFC.5512"?> <?rfc include="reference.RFC.5565"?> <?rfc include="reference.RFC.7490"?> </references><section numbered="false" toc="default"> <name>Contributors</name> <contact fullname="Uma Chunduri"> <organization>Huawei</organization> <address> <email>uma.chunduri@gmail.com</email> </address> </contact> </section> </back> </rfc>