| < draft-ietf-ospf-te-link-attr-reuse-09.txt | draft-ietf-ospf-te-link-attr-reuse-10.txt > | |||
|---|---|---|---|---|
| LSR Working Group P. Psenak, Ed. | LSR Working Group P. Psenak, Ed. | |||
| Internet-Draft L. Ginsberg | Internet-Draft L. Ginsberg | |||
| Intended status: Standards Track Cisco Systems | Intended status: Standards Track Cisco Systems | |||
| Expires: March 22, 2020 W. Henderickx | Expires: May 2, 2020 W. Henderickx | |||
| Nokia | Nokia | |||
| J. Tantsura | J. Tantsura | |||
| Apstra | Apstra | |||
| J. Drake | J. Drake | |||
| Juniper Networks | Juniper Networks | |||
| September 19, 2019 | October 30, 2019 | |||
| OSPF Link Traffic Engineering Attribute Reuse | OSPF Link Traffic Engineering Attribute Reuse | |||
| draft-ietf-ospf-te-link-attr-reuse-09.txt | draft-ietf-ospf-te-link-attr-reuse-10.txt | |||
| Abstract | Abstract | |||
| Various link attributes have been defined in OSPF in the context of | Various link attributes have been defined in OSPF in the context of | |||
| the MPLS Traffic Engineering (TE) and GMPLS. Many of these link | the MPLS Traffic Engineering (TE) and GMPLS. Since the original | |||
| attributes can be used for applications other than MPLS TE or GMPLS. | RSVP-TE use case was defined, additional applications (e.g., SRTE, | |||
| This document defines how to distribute such attributes in OSPFv2 and | LFA) have been defined which also make use of the link attribute | |||
| OSPFv3 for applications other than MPLS TE or GMPLS. | advertisements. This document defines how to distribute link | |||
| attributes in OSPFv2 and OSPFv3 for applications other than MPLS TE | ||||
| or GMPLS. | ||||
| Status of This Memo | Status of This Memo | |||
| This Internet-Draft is submitted in full conformance with the | This Internet-Draft is submitted in full conformance with the | |||
| provisions of BCP 78 and BCP 79. | provisions of BCP 78 and BCP 79. | |||
| Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
| Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
| working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
| Drafts is at https://datatracker.ietf.org/drafts/current/. | Drafts is at https://datatracker.ietf.org/drafts/current/. | |||
| Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
| and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
| time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
| material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
| This Internet-Draft will expire on March 22, 2020. | This Internet-Draft will expire on May 2, 2020. | |||
| Copyright Notice | Copyright Notice | |||
| Copyright (c) 2019 IETF Trust and the persons identified as the | Copyright (c) 2019 IETF Trust and the persons identified as the | |||
| document authors. All rights reserved. | document authors. All rights reserved. | |||
| This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
| Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
| (https://trustee.ietf.org/license-info) in effect on the date of | (https://trustee.ietf.org/license-info) in effect on the date of | |||
| publication of this document. Please review these documents | publication of this document. Please review these documents | |||
| skipping to change at page 2, line 27 ¶ | skipping to change at page 2, line 31 ¶ | |||
| 3. Advertisement of Application Specific Values . . . . . . . . 4 | 3. Advertisement of Application Specific Values . . . . . . . . 4 | |||
| 4. Reused TE link attributes . . . . . . . . . . . . . . . . . . 7 | 4. Reused TE link attributes . . . . . . . . . . . . . . . . . . 7 | |||
| 4.1. Shared Risk Link Group (SRLG) . . . . . . . . . . . . . . 7 | 4.1. Shared Risk Link Group (SRLG) . . . . . . . . . . . . . . 7 | |||
| 4.2. Extended Metrics . . . . . . . . . . . . . . . . . . . . 8 | 4.2. Extended Metrics . . . . . . . . . . . . . . . . . . . . 8 | |||
| 4.3. Administrative Group . . . . . . . . . . . . . . . . . . 9 | 4.3. Administrative Group . . . . . . . . . . . . . . . . . . 9 | |||
| 4.4. TE Metric . . . . . . . . . . . . . . . . . . . . . . . . 9 | 4.4. TE Metric . . . . . . . . . . . . . . . . . . . . . . . . 9 | |||
| 5. Maximum Link Bandwidth . . . . . . . . . . . . . . . . . . . 9 | 5. Maximum Link Bandwidth . . . . . . . . . . . . . . . . . . . 9 | |||
| 6. Local Interface IPv6 Address Sub-TLV . . . . . . . . . . . . 10 | 6. Local Interface IPv6 Address Sub-TLV . . . . . . . . . . . . 10 | |||
| 7. Remote Interface IPv6 Address Sub-TLV . . . . . . . . . . . . 10 | 7. Remote Interface IPv6 Address Sub-TLV . . . . . . . . . . . . 10 | |||
| 8. Deployment Considerations . . . . . . . . . . . . . . . . . . 10 | 8. Deployment Considerations . . . . . . . . . . . . . . . . . . 10 | |||
| 9. Attribute Advertisements and Enablement . . . . . . . . . . . 10 | 8.1. Use of TE LSA Advertisements . . . . . . . . . . . . . . 10 | |||
| 10. Backward Compatibility . . . . . . . . . . . . . . . . . . . 11 | 8.2. Use of Zero Length Application Identifier Bit Masks . . . 11 | |||
| 11. Security Considerations . . . . . . . . . . . . . . . . . . . 12 | 9. Attribute Advertisements and Enablement . . . . . . . . . . . 11 | |||
| 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 | 10. Backward Compatibility . . . . . . . . . . . . . . . . . . . 12 | |||
| 12.1. OSPFv2 . . . . . . . . . . . . . . . . . . . . . . . . . 12 | 11. Security Considerations . . . . . . . . . . . . . . . . . . . 13 | |||
| 12.2. OSPFv3 . . . . . . . . . . . . . . . . . . . . . . . . . 13 | 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 | |||
| 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 14 | 12.1. OSPFv2 . . . . . . . . . . . . . . . . . . . . . . . . . 13 | |||
| 14. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14 | 12.2. OSPFv3 . . . . . . . . . . . . . . . . . . . . . . . . . 14 | |||
| 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 | 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 15 | |||
| 14. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 15 | ||||
| 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 | ||||
| 15.1. Normative References . . . . . . . . . . . . . . . . . . 15 | 15.1. Normative References . . . . . . . . . . . . . . . . . . 15 | |||
| 15.2. Informative References . . . . . . . . . . . . . . . . . 15 | 15.2. Informative References . . . . . . . . . . . . . . . . . 16 | |||
| Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 | Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18 | |||
| 1. Introduction | 1. Introduction | |||
| Various link attributes have been defined in OSPFv2 [RFC2328] and | Various link attributes have been defined in OSPFv2 [RFC2328] and | |||
| OSPFv3 [RFC5340] in the context of the MPLS TE and GMPLS. All these | OSPFv3 [RFC5340] in the context of the MPLS TE and GMPLS. All these | |||
| attributes are distributed by OSPFv2 as sub-TLVs of the Link-TLV | attributes are distributed by OSPFv2 as sub-TLVs of the Link-TLV | |||
| advertised in the OSPFv2 TE Opaque LSA [RFC3630]. In OSPFv3, they | advertised in the OSPFv2 TE Opaque LSA [RFC3630]. In OSPFv3, they | |||
| are distributed as sub-TLVs of the Link-TLV advertised in the OSPFv3 | are distributed as sub-TLVs of the Link-TLV advertised in the OSPFv3 | |||
| Intra-Area-TE-LSA as defined in [RFC5329]. | Intra-Area-TE-LSA as defined in [RFC5329]. | |||
| skipping to change at page 5, line 10 ¶ | skipping to change at page 5, line 16 ¶ | |||
| The ASLA sub-TLV is an optional sub-TLV and can appear multiple times | The ASLA sub-TLV is an optional sub-TLV and can appear multiple times | |||
| in the OSPFv2 Extended Link TLV and OSPFv3 Router-Link TLV. It has | in the OSPFv2 Extended Link TLV and OSPFv3 Router-Link TLV. It has | |||
| the following format: | the following format: | |||
| 0 1 2 3 | 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 | 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 | | | Type | Length | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | SABML | UDABML | Reserved | | | SABM Length | UDABM Length | Reserved | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | Standard Application Bit-Mask | | | Standard Application Identifier Bit-Mask | | |||
| +- -+ | +- -+ | |||
| | ... | | | ... | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | User Defined Application Bit-Mask | | | User Defined Application Identifier Bit-Mask | | |||
| +- -+ | +- -+ | |||
| | ... | | | ... | | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | Link Attribute sub-sub-TLVs | | | Link Attribute sub-sub-TLVs | | |||
| +- -+ | +- -+ | |||
| | ... | | | ... | | |||
| where: | where: | |||
| Type: 10 (OSPFv2), 11 (OSPFv3) | Type: 10 (OSPFv2), 11 (OSPFv3) | |||
| Length: variable | Length: variable | |||
| SABML: Standard Application Bit-Mask Length. It MUST be a | SABM Length: Standard Application Identifier Bit-Mask Length. It | |||
| multiple of 4 bytes. If the Standard Application Bit-Mask is not | MUST be a multiple of 4 bytes. If the Standard Application Bit- | |||
| present, the Standard Application Bit-Mask Length MUST be set to | Mask is not present, the Standard Application Bit-Mask Length MUST | |||
| 0. | be set to 0. | |||
| UDABML: User Defined Application Bit-Mask Length. It MUST be a | UDABM Length: User Defined Application Identifier Bit-Mask Length. | |||
| multiple of 4 bytes. If the User Defined Application Bit-Mask is | It MUST be a multiple of 4 bytes. If the User Defined Application | |||
| not present, the User Defined Application Bit-Mask Length MUST be | Bit-Mask is not present, the User Defined Application Bit-Mask | |||
| set to 0. | Length MUST be set to 0. | |||
| Standard Application Bit-Mask: Optional set of bits, where each | Standard Application Identifier Bit-Mask: Optional set of bits, | |||
| bit represents a single standard application. Bits are defined in | where each bit represents a single standard application. Bits are | |||
| [I-D.ietf-isis-te-app], which also request a new IANA "Link | defined in [I-D.ietf-isis-te-app], which also request a new IANA | |||
| Attribute Applications" registry under "Interior Gateway Protocol | "Link Attribute Applications" registry under "Interior Gateway | |||
| (IGP) Parameters" for them. The bits are repeated here for | Protocol (IGP) Parameters" for them. The bits are repeated here | |||
| informational purpose: | for informational purpose: | |||
| Bit-0: RSVP TE | Bit-0 (R-bit): RSVP TE | |||
| Bit-1: Segment Routing TE | Bit-1 (S-bit): Segment Routing TE | |||
| Bit-2: Loop Free Alternate (LFA). Includes all LFA types | Bit-2 (F-bit): Loop Free Alternate (LFA). Includes all LFA | |||
| Bit-3: Flexible Algorithm | types | |||
| User Defined Application Bit-Mask: Optional set of bits, where | User Defined Application Identifier Bit-Mask: Optional set of | |||
| each bit represents a single user defined application. | bits, where each bit represents a single user defined application. | |||
| Standard Application Bits are defined/sent starting with Bit 0. | Standard Application Identifier Bits are defined/sent starting with | |||
| Additional bit definitions that are defined in the future SHOULD be | Bit 0. Additional bit definitions that are defined in the future | |||
| assigned in ascending bit order so as to minimize the number of | SHOULD be assigned in ascending bit order so as to minimize the | |||
| octets that will need to be transmitted. | number of octets that will need to be transmitted. | |||
| User Defined Application bits have no relationship to Standard | User Defined Application Identifier Bits have no relationship to | |||
| Application bits and are NOT managed by IANA or any other standards | Standard Application bits and are NOT managed by IANA or any other | |||
| body. It is recommended that bits are used starting with Bit 0 so as | standards body. It is recommended that bits are used starting with | |||
| to minimize the number of octets required to advertise all of them. | Bit 0 so as to minimize the number of octets required to advertise | |||
| all of them. | ||||
| Undefined bits in both Bit-Masks MUST be transmitted as 0 and MUST be | Undefined bits in both Bit-Masks MUST be transmitted as 0 and MUST be | |||
| ignored on receipt. Bits that are NOT transmitted MUST be treated as | ignored on receipt. Bits that are NOT transmitted MUST be treated as | |||
| if they are set to 0 on receipt. | if they are set to 0 on receipt. | |||
| If the link attribute advertisement is limited to be used by a | If the link attribute advertisement is limited to be used by a | |||
| specific set of applications, corresponding Bit-Masks MUST be present | specific set of applications, corresponding Bit-Masks MUST be present | |||
| and application specific bit(s) MUST be set for all applications that | and application specific bit(s) MUST be set for all applications that | |||
| use the link attributes advertised in the ASLA sub-TLV. | use the link attributes advertised in the ASLA sub-TLV. | |||
| Application Bit-Masks apply to all link attributes that support | Application Bit-Masks apply to all link attributes that support | |||
| application specific values and are advertised in the ASLA sub-TLV. | application specific values and are advertised in the ASLA sub-TLV. | |||
| The advantage of not making the Application Bit-Masks part of the | The advantage of not making the Application Bit-Masks part of the | |||
| attribute advertisement itself is that we can keep the format of the | attribute advertisement itself is that we can keep the format of the | |||
| link attributes that have been defined previously and reuse the same | link attributes that have been defined previously and reuse the same | |||
| format when advertising them in the ASLA sub-TLV. | format when advertising them in the ASLA sub-TLV. | |||
| When neither the Standard Application Bits nor the User Defined | When neither the Standard Application Bits nor the User Defined | |||
| Application bits are set (i.e., both SABML and UDABML are 0) in the | Application bits are set (i.e., both SABM Length and UDABM Length are | |||
| ASLA sub-TLV, then the link attributes included in it MUST be | 0) in the ASLA sub-TLV, then the link attributes included in it MUST | |||
| considered as being applicable to all applications. | be considered as being applicable to all applications. | |||
| If, however, another advertisement of the same link attribute | If, however, another advertisement of the same link attribute | |||
| includes any Application Bit-Mask in the ASLA sub-TLV, applications | includes any Application Bit-Mask in the ASLA sub-TLV, applications | |||
| that are listed in the Application Bit-Masks of such ASLA sub-TLV | that are listed in the Application Bit-Masks of such ASLA sub-TLV | |||
| SHOULD use the attribute advertisement which has the application | SHOULD use the attribute advertisement which has the application | |||
| specific bit set in the Application Bit-Masks. | specific bit set in the Application Bit-Masks. | |||
| If the same application is listed in the Application Bit-Masks of | If the same application is listed in the Application Bit-Masks of | |||
| more then one ASLA sub-TLV, the application SHOULD use the first | more then one ASLA sub-TLV, the application SHOULD use the first | |||
| advertisement and ignore any subsequent advertisements of the same | advertisement and ignore any subsequent advertisements of the same | |||
| skipping to change at page 9, line 10 ¶ | skipping to change at page 9, line 10 ¶ | |||
| 18 - Unidirectional Available Bandwidth | 18 - Unidirectional Available Bandwidth | |||
| 19 - Unidirectional Utilized Bandwidth | 19 - Unidirectional Utilized Bandwidth | |||
| 4.3. Administrative Group | 4.3. Administrative Group | |||
| [RFC3630] and [RFC7308] define the Administrative Group and Extended | [RFC3630] and [RFC7308] define the Administrative Group and Extended | |||
| Administrative Group sub-TLVs respectively. | Administrative Group sub-TLVs respectively. | |||
| One use case where advertisement of the Extended Administrative | ||||
| Group(s) for a link is required is described in | ||||
| [I-D.ietf-lsr-flex-algo]. | ||||
| To advertise the Administrative Group and Extended Administrative | To advertise the Administrative Group and Extended Administrative | |||
| Group in the OSPFv2 Extended Link TLV, the same format for the sub- | Group in the OSPFv2 Extended Link TLV, the same format for the sub- | |||
| TLVs defined in [RFC3630] and [RFC7308] is used with the following | TLVs defined in [RFC3630] and [RFC7308] is used with the following | |||
| TLV types: | TLV types: | |||
| 19 - Administrative Group | 19 - Administrative Group | |||
| 20 - Extended Administrative Group | 20 - Extended Administrative Group | |||
| To advertise Administrative Group and Extended Administrative Group | To advertise Administrative Group and Extended Administrative Group | |||
| skipping to change at page 10, line 35 ¶ | skipping to change at page 10, line 31 ¶ | |||
| Because it is an application independent attribute, it MUST NOT be | Because it is an application independent attribute, it MUST NOT be | |||
| advertised in the ASLA sub-TLV. Instead, it MAY be advertised as a | advertised in the ASLA sub-TLV. Instead, it MAY be advertised as a | |||
| sub-TLV of the OSPFv3 E-Router-LSA Router-Link TLV [RFC8362]. | sub-TLV of the OSPFv3 E-Router-LSA Router-Link TLV [RFC8362]. | |||
| To advertise the Remote Interface IPv6 Address Sub-TLV in the OSPFv3 | To advertise the Remote Interface IPv6 Address Sub-TLV in the OSPFv3 | |||
| Router-Link TLV, the same format for sub-TLV defined in [RFC5329] is | Router-Link TLV, the same format for sub-TLV defined in [RFC5329] is | |||
| used with TLV type 25. | used with TLV type 25. | |||
| 8. Deployment Considerations | 8. Deployment Considerations | |||
| 8.1. Use of TE LSA Advertisements | ||||
| Bit Identifers for Standard Applications are defined in Section 3. | ||||
| All of the identifiers defined in this document are associated with | ||||
| applications which were already deployed in some networks prior to | ||||
| the writing of this document. Therefore, such applications have been | ||||
| deployed using the TE LSA advertisements. The Standard Applications | ||||
| defined in this document MAY continue to use TE LSA advertisements | ||||
| for a given link so long as at least one of the following conditions | ||||
| is true: | ||||
| The application is RSVP-TE | ||||
| The application is SRTE or LFA and RSVP-TE is not deployed | ||||
| anywhere in the network | ||||
| The application is SRTE or LFA, RSVP-TE is deployed in the | ||||
| network, and both the set of links on which SRTE and/or LFA | ||||
| advertisements are required and the attribute values used by SRTE | ||||
| and/or LFA on all such links is fully congruent with the links and | ||||
| attribute values used by RSVP-TE | ||||
| Under the conditions defined above, implementations which support the | ||||
| extensions defined in this document have the choice of using TE LSA | ||||
| advertisements or application specific advertisements in support of | ||||
| SRTE and/or LFA. This will require implementations to provide | ||||
| controls specifying which type of advertisements are to be sent/ | ||||
| processed on receive for these applications. Further discussion of | ||||
| the associated issues can be found in Section 10. | ||||
| New applications which future documents define to make use of the | ||||
| advertisements defined in this document MUST NOT make use of TE LSA | ||||
| advertisements. | ||||
| 8.2. Use of Zero Length Application Identifier Bit Masks | ||||
| If link attributes are advertised associated with zero length | If link attributes are advertised associated with zero length | |||
| application bit masks for both standard applications and user defined | Application Identifier Bit-Masks for both standard applications and | |||
| applications, then that set of link attributes MAY be used by any | user defined applications, then that set of link attributes MAY be | |||
| application. If support for a new application is introduced on any | used by any application. If support for a new application is | |||
| node in a network in the presence of such advertisements, these | introduced on any node in a network in the presence of such | |||
| advertisements MAY be used by the new application. If this is not | advertisements, these advertisements MAY be used by the new | |||
| what is intended, then existing advertisements MUST be readvertised | application. If this is not what is intended, then existing | |||
| with an explicit set of applications specified before a new | advertisements MUST be readvertised with an explicit set of | |||
| application is introduced. | applications specified before a new application is introduced. | |||
| 9. Attribute Advertisements and Enablement | 9. Attribute Advertisements and Enablement | |||
| This document defines extensions to support the advertisement of | This document defines extensions to support the advertisement of | |||
| application specific link attributes. | application specific link attributes. | |||
| Whether the presence of link attribute advertisements for a given | Whether the presence of link attribute advertisements for a given | |||
| application indicates that the application is enabled on that link | application indicates that the application is enabled on that link | |||
| depends upon the application. Similarly, whether the absence of link | depends upon the application. Similarly, whether the absence of link | |||
| attribute advertisements indicates that the application is not | attribute advertisements indicates that the application is not | |||
| enabled depends upon the application. | enabled depends upon the application. | |||
| In the case of RSVP-TE, the advertisement of application specific | In the case of RSVP-TE, the advertisement of application specific | |||
| link attributes implies that RSVP is enabled on that link. | link attributes implies that RSVP is enabled on that link. The | |||
| absence of RSVP-TE application specific link attributes in | ||||
| combination with the absence of legacy advertisements implies that | ||||
| RSVP is NOT enabled on that link. | ||||
| In the case of SRTE, advertisement of application specific link | In the case of SRTE, advertisement of application specific link | |||
| attributes does NOT indicate enablement of SRTE. The advertisements | attributes does NOT indicate enablement of SRTE. The advertisements | |||
| are only used to support constraints which may be applied when | are only used to support constraints which may be applied when | |||
| specifying an explicit path. SRTE is implicitly enabled on all links | specifying an explicit path. SRTE is implicitly enabled on all links | |||
| which are part of the Segment Routing enabled topology independent of | which are part of the Segment Routing enabled topology independent of | |||
| the existence of link attribute advertisements. | the existence of link attribute advertisements. | |||
| In the case of LFA, advertisement of application specific link | In the case of LFA, advertisement of application specific link | |||
| attributes does NOT indicate enablement of LFA on that link. | attributes does NOT indicate enablement of LFA on that link. | |||
| Enablement is controlled by local configuration. | Enablement is controlled by local configuration. | |||
| In the case of Flexible Algorithm, advertisement of application | ||||
| specific link attributes does NOT indicate enablement of Flexible | ||||
| Algorithm on that link. Rather the attributes are used to determine | ||||
| what links are included/excluded in the algorithm specific | ||||
| constrained SPF. This is fully specified in | ||||
| [I-D.ietf-lsr-flex-algo]. | ||||
| If, in the future, additional standard applications are defined to | If, in the future, additional standard applications are defined to | |||
| use this mechanism, the specification defining this use MUST define | use this mechanism, the specification defining this use MUST define | |||
| the relationship between application specific link attribute | the relationship between application specific link attribute | |||
| advertisements and enablement for that application. | advertisements and enablement for that application. | |||
| This document allows the advertisement of application specific link | This document allows the advertisement of application specific link | |||
| attributes with no application identifiers i.e., both the Standard | attributes with no application identifiers i.e., both the Standard | |||
| Application Bit Mask and the User Defined Application Bit Mask are | Application Identifier Bit-Mask and the User Defined Application Bit | |||
| not present (See Section 3). This supports the use of the link | Mask are not present (See Section 3). This supports the use of the | |||
| attribute by any application. In the presence of an application | link attribute by any application. In the presence of an application | |||
| where the advertisement of link attribute advertisements is used to | where the advertisement of link attribute advertisements is used to | |||
| infer the enablement of an application on that link (e.g., RSVP-TE), | infer the enablement of an application on that link (e.g., RSVP-TE), | |||
| the absence of the application identifier leaves ambiguous whether | the absence of the Application Identifier leaves ambiguous whether | |||
| that application is enabled on such a link. This needs to be | that application is enabled on such a link. This needs to be | |||
| considered when making use of the "any application" encoding. | considered when making use of the "any application" encoding. | |||
| 10. Backward Compatibility | 10. Backward Compatibility | |||
| Link attributes may be concurrently advertised in both the TE Opaque | Link attributes may be concurrently advertised in both the TE Opaque | |||
| LSA and the Extended Link Opaque LSA in OSPFv2 and the OSPFv3 Intra- | LSA and the Extended Link Opaque LSA in OSPFv2 and the OSPFv3 Intra- | |||
| Area-TE-LSA and OSPFv3 Extended LSA Router-Link TLV in OSPFv3. | Area-TE-LSA and OSPFv3 Extended LSA Router-Link TLV in OSPFv3. | |||
| In fact, there is at least one OSPF implementation that utilizes the | In fact, there is at least one OSPF implementation that utilizes the | |||
| link attributes advertised in TE Opaque LSAs [RFC3630] for Non-RSVP | link attributes advertised in TE Opaque LSAs [RFC3630] for Non-RSVP | |||
| TE applications. For example, this implementation of LFA and remote | TE applications. For example, this implementation of LFA and remote | |||
| LFA utilizes links attributes such as Shared Risk Link Groups (SRLG) | LFA utilizes links attributes such as Shared Risk Link Groups (SRLG) | |||
| [RFC4203] and Admin Group [[RFC3630] advertised in TE Opaque LSAs. | [RFC4203] and Admin Group [[RFC3630] advertised in TE Opaque LSAs. | |||
| These applications are described in [RFC5286], [RFC7490], [RFC7916] | These applications are described in [RFC5286], [RFC7490], [RFC7916] | |||
| and [RFC8102]. | and [RFC8102]. | |||
| When an OSPF routing domain includes routers using link attributes | When an OSPF routing domain includes routers using link attributes | |||
| from the OSPFv2 TE Opaque LSAs or the OSPFv3 Intra-Area-TE-LSA for | from the OSPFv2 TE Opaque LSAs or the OSPFv3 Intra-Area-TE-LSA for | |||
| Non-RSVP TE applications such as LFA, OSPF routers in that domain | Non-RSVP TE applications defined in this document (i.e. SRTE and | |||
| SHOULD continue to advertise such OSPFv2 TE Opaque LSAs or the OSPFv3 | LFA), OSPF routers in that domain SHOULD continue to advertise such | |||
| Intra-Area-TE-LSA. If there are also OSPF routers using the link | OSPFv2 TE Opaque LSAs or the OSPFv3 Intra-Area-TE-LSA. In such a | |||
| attributes described herein for any other application, OSPF routers | deployment, the advertised attributes SHOULD be the same and Non- | |||
| in the routing domain will also need to advertise these attributes in | ||||
| OSPFv2 Extended Link Attributes LSAs or OSPFv3 E-Router-LSA. In such | ||||
| a deployment, the advertised attributes SHOULD be the same and Non- | ||||
| RSVP application access to link attributes is a matter of local | RSVP application access to link attributes is a matter of local | |||
| policy. | policy. | |||
| When advertising link-attributes for any new applications other then | ||||
| RSVP-TE, SRTE or LFA, OSPF routers MUST NOT use TE Opaque LSA or | ||||
| OSPFv3 Intra-Area-TE-LSA. Instead, advertisement in the OSPFv2 | ||||
| Extended Link Attributes LSAs or OSPFv3 E-Router-LSA MUST be used. | ||||
| It is RECOMMENDED to advertise link-attributes for RSVP-TE in the | ||||
| existing TE LSAs. | ||||
| 11. Security Considerations | 11. Security Considerations | |||
| Existing security extensions as described in [RFC2328], [RFC5340] and | Existing security extensions as described in [RFC2328], [RFC5340] and | |||
| [RFC8362] apply to extensions defined in this document. While OSPF | [RFC8362] apply to extensions defined in this document. While OSPF | |||
| is under a single administrative domain, there can be deployments | is under a single administrative domain, there can be deployments | |||
| where potential attackers have access to one or more networks in the | where potential attackers have access to one or more networks in the | |||
| OSPF routing domain. In these deployments, stronger authentication | OSPF routing domain. In these deployments, stronger authentication | |||
| mechanisms such as those specified in [RFC5709], [RFC7474], [RFC4552] | mechanisms such as those specified in [RFC5709], [RFC7474], [RFC4552] | |||
| or [RFC7166] SHOULD be used. | or [RFC7166] SHOULD be used. | |||
| skipping to change at page 15, line 45 ¶ | skipping to change at page 16, line 34 ¶ | |||
| [RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and | [RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and | |||
| F. Baker, "OSPFv3 Link State Advertisement (LSA) | F. Baker, "OSPFv3 Link State Advertisement (LSA) | |||
| Extensibility", RFC 8362, DOI 10.17487/RFC8362, April | Extensibility", RFC 8362, DOI 10.17487/RFC8362, April | |||
| 2018, <https://www.rfc-editor.org/info/rfc8362>. | 2018, <https://www.rfc-editor.org/info/rfc8362>. | |||
| 15.2. Informative References | 15.2. Informative References | |||
| [I-D.ietf-isis-te-app] | [I-D.ietf-isis-te-app] | |||
| Ginsberg, L., Psenak, P., Previdi, S., Henderickx, W., and | Ginsberg, L., Psenak, P., Previdi, S., Henderickx, W., and | |||
| J. Drake, "IS-IS TE Attributes per application", draft- | J. Drake, "IS-IS TE Attributes per application", draft- | |||
| ietf-isis-te-app-06 (work in progress), April 2019. | ietf-isis-te-app-08 (work in progress), October 2019. | |||
| [I-D.ietf-lsr-flex-algo] | ||||
| Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and | ||||
| A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex- | ||||
| algo-04 (work in progress), September 2019. | ||||
| [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, | [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, | |||
| DOI 10.17487/RFC2328, April 1998, | DOI 10.17487/RFC2328, April 1998, | |||
| <https://www.rfc-editor.org/info/rfc2328>. | <https://www.rfc-editor.org/info/rfc2328>. | |||
| [RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in | [RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in | |||
| Support of Generalized Multi-Protocol Label Switching | Support of Generalized Multi-Protocol Label Switching | |||
| (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005, | (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005, | |||
| <https://www.rfc-editor.org/info/rfc4203>. | <https://www.rfc-editor.org/info/rfc4203>. | |||
| End of changes. 30 change blocks. | ||||
| 90 lines changed or deleted | 123 lines changed or added | |||
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