diff --git a/draft-cppy-grow-bmp-path-marking-tlv.txt b/draft-cppy-grow-bmp-path-marking-tlv.txt index b5e9019..2558cc5 100644 --- a/draft-cppy-grow-bmp-path-marking-tlv.txt +++ b/draft-cppy-grow-bmp-path-marking-tlv.txt @@ -5,17 +5,17 @@ Network Working Group C. Cardona Internet-Draft P. Lucente Intended status: Standards Track NTT -Expires: April 22, 2023 P. Francois +Expires: 11 September 2023 P. Francois INSA-Lyon Y. Gu Huawei T. Graf Swisscom - Oct 19, 2022 + 10 March 2023 BMP Extension for Path Status TLV - draft-cppy-grow-bmp-path-marking-tlv-11 + draft-cppy-grow-bmp-path-marking-tlv-12 Abstract @@ -24,8 +24,8 @@ Abstract Route Monitoring (RM) messages. This document proposes an extension to BMP to convey the status of a path after being processed by the BGP process. This extension makes use of the TLV mechanims described - in draft-ietf-grow-bmp-tlv [I-D.ietf-grow-bmp-tlv] and draft-ietf- - grow-bmp-tlv-ebit [I-D.ietf-grow-bmp-tlv-ebit]. + in draft-ietf-grow-bmp-tlv [I-D.ietf-grow-bmp-tlv] and + draft-ietf-grow-bmp-tlv-ebit [I-D.ietf-grow-bmp-tlv-ebit]. Requirements Language @@ -53,39 +53,44 @@ Status of This Memo -Cardona, et al. Expires April 22, 2023 [Page 1] +Cardona, et al. Expires 11 September 2023 [Page 1] -Internet-Draft BMP path status tlv Oct 2022 +Internet-Draft BMP path status tlv March 2023 - This Internet-Draft will expire on April 22, 2023. + This Internet-Draft will expire on 11 September 2023. Copyright Notice - Copyright (c) 2022 IETF Trust and the persons identified as the + Copyright (c) 2023 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 - (https://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. + Provisions Relating to IETF Documents (https://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 Revised BSD License text as + described in Section 4.e of the Trust Legal Provisions and are + provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Path Status TLV . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. IANA-registered Path Status TLV . . . . . . . . . . . . . 3 - 2.2. Enterprise-specific Path Status TLV . . . . . . . . . . . 6 - 3. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6 - 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 - 5. Security Considerations . . . . . . . . . . . . . . . . . . . 7 - 6. Normative References . . . . . . . . . . . . . . . . . . . . 7 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 + 2.2. Enterprise-specific Path Status TLV . . . . . . . . . . . 5 + 3. Implementation notes . . . . . . . . . . . . . . . . . . . . 6 + 3.1. Configuration of BMP path marking . . . . . . . . . . . . 7 + 3.2. Paths with no markings . . . . . . . . . . . . . . . . . 7 + 3.3. Significance of status and origin RIBs . . . . . . . . . 7 + 3.4. Enterprise-specific status and reasons . . . . . . . . . 8 + 3.5. Multiple TLVs assigned to the same route. . . . . . . . . 8 + 4. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 8 + 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 + 6. Security Considerations . . . . . . . . . . . . . . . . . . . 8 + 7. Normative References . . . . . . . . . . . . . . . . . . . . 8 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 1. Introduction @@ -101,18 +106,19 @@ Table of Contents troubleshooting. Having such status stored in a centralized system can enable the development of tools that facilitate this process. Optimisation systems can include the path status in their process, - and also use the status as a validation source (since it can compare - the calculated state to the actual outcome of the network, such as - primary and backup path). As a final example, path status - information can complement other centralized sources of data, for - example, flow collectors. -Cardona, et al. Expires April 22, 2023 [Page 2] +Cardona, et al. Expires 11 September 2023 [Page 2] -Internet-Draft BMP path status tlv Oct 2022 +Internet-Draft BMP path status tlv March 2023 + + and also use the status as a validation source (since it can compare + the calculated state to the actual outcome of the network, such as + primary and backup path). As a final example, path status + information can complement other centralized sources of data, for + example, flow collectors. This document defines a so-called Path Status TLV to convey the BGP path status to the BMP server. The BMP Path Status TLV is carried in @@ -139,41 +145,45 @@ Internet-Draft BMP path status tlv Oct 2022 Figure 2: Encoding of IANA-Registered Path Status TLV - o E bit: For an IANA-registered TLV, the E bit MUST be set to 0. + * E bit: For an IANA-registered TLV, the E bit MUST be set to 0 + [I-D.ietf-grow-bmp-tlv-ebit]. - o Type = TBD2 (15 Bits): indicates that it is the IANA-registered + * Type = TBD2 (15 Bits): indicates that it is the IANA-registered Path Status TLV. - o Length (2 Octets): indicates the length of the value field of the + * Length (2 Octets): indicates the length of the value field of the Path Status TLV. The value field further consists of the Path- Status field and Reason Code field. - o Index (2 Octets): indicates the prefix that this TLV is - describing. The index is the encapsulation order, starting from - 0, of the prefix in the BGP Update PDU. + * Index (2 Octets): indicates the prefix that this TLV is + describing. Please see [I-D.ietf-grow-bmp-tlv] for details of the + use of the index field to associate the path marking content with + one or more NLRIs. + + + + + + +Cardona, et al. Expires 11 September 2023 [Page 3] + +Internet-Draft BMP path status tlv March 2023 + - o Path Status (4 Octets): indicates the path status of the BGP + * Path Status (4 Octets): indicates the path status of the BGP Update PDU encapsulated in the RM Message. Currently 10 types of path status are defined, as shown in Table 1. All zeros are reserved. - o Reason Code (2 Octets, optional): indicates the reason of the path + * Reason Code (2 Octets, optional): indicates the reason of the path status indicated in the Path Status field. The reason code field is optional. If no reason code is carried, this field is empty. If a reason code is carried, the reason code is indicated by a 2-byte value, which is defined in Table 2. - - -Cardona, et al. Expires April 22, 2023 [Page 3] - -Internet-Draft BMP path status tlv Oct 2022 - - +------------+-----------------------------+ | Value | Path type | +------------------------------------------+ - | 0x00000000 | Reserved | | 0x00000001 | Invalid | | 0x00000002 | Best | | 0x00000004 | Non-selected | @@ -189,44 +199,49 @@ Internet-Draft BMP path status tlv Oct 2022 Table 1: IANA-Registered Path Type + Figure 1 + The Path Status field contains a bitmap where each bit encodes a specific role of the path. Multiple bits may be set when multiple path status apply to a path. - o The best-path is defined in RFC4271 [RFC4271] and the best- + * The best-path is defined in RFC4271 [RFC4271] and the best- external path is defined in draft-ietf-idr-best-external [I-D.ietf-idr-best-external]. - o An invalid path is a route that does not enter the BGP decision + * An invalid path is a route that does not enter the BGP decision process. - o A non-selected path is a route that is not selected in the BGP + * A non-selected path is a route that is not selected in the BGP decision process. Back-up routes are considered non-selected, while the best and ECMP routes are not considered as non-selected. - o A primary path is a recursive or non-recursive path whose nexthop - resolution ends with an adjacency draft-ietf-rtgwg-bgp-pic - [I-D.ietf-rtgwg-bgp-pic]. A prefix can have more than one primary - path if multipath is configured draft-lapukhov-bgp-ecmp- - considerations [I-D.lapukhov-bgp-ecmp-considerations]. A best- - path is also considered as a primary path. - o A backup path is also installed in the RIB, but it is not used - until some or all primary paths become unreachable. Backup paths - are used for fast convergence in the event of failures. - o A non-installed path refers to the route that is not installed - into the IP routing table. - -Cardona, et al. Expires April 22, 2023 [Page 4] +Cardona, et al. Expires 11 September 2023 [Page 4] -Internet-Draft BMP path status tlv Oct 2022 +Internet-Draft BMP path status tlv March 2023 + + + * A primary path is a recursive or non-recursive path whose nexthop + resolution ends with an adjacency draft-ietf-rtgwg-bgp-pic + [I-D.ietf-rtgwg-bgp-pic]. A prefix can have more than one primary + path if multipath is configured + draft-lapukhov-bgp-ecmp-considerations + [I-D.lapukhov-bgp-ecmp-considerations]. A best-path is also + considered as a primary path. + * A backup path is also installed in the RIB, but it is not used + until some or all primary paths become unreachable. Backup paths + are used for fast convergence in the event of failures. - o For the advertisement of multiple paths for the same address + * A non-installed path refers to the route that is not installed + into the IP routing table. + + * For the advertisement of multiple paths for the same address prefix without the new paths implicitly replacing any previous ones, the add-path status is applied [RFC7911]. @@ -237,52 +252,35 @@ Internet-Draft BMP path status tlv Oct 2022 +----------+-----------------------------------------------------+ | Value | Reason code | +----------------------------------------------------------------+ - | [0x0001] | invalid for super network | - | [0x0002] | invalid for dampening | - | [0x0003] | invalid for damping history | - | [0x0005] | invalid for ROV not valid | - | [0x0006] | invalid for interface error | - | [0x0007] | invalid for nexthop route unreachable | - | [0x0008] | invalid for nexthop tunnel unreachable | - | [0x0009] | invalid for nexthop restrain | - | [0x000A] | invalid for not supporting BGP LSP relay | - | [0x000B] | invalid for being inactive within VPN insance | - | [0x000C] | invalid for prefix sid not exist | - | [0x000D] | not preferred for peer address | - | [0x000E] | not preferred for router ID | - | [0x000F] | not preferred for Cluster List | - | [0x0010] | not preferred for IGP cost | - | [0x0011] | not preferred for peer type | - | [0x0012] | not preferred for MED | - | [0x0013] | not preferred for origin | - | [0x0014] | not preferred for AS Path | - | [0x0015] | not preferred for route type | + | [0x0007] | invalid for AS loop | + | [0x0007] | invalid for unresolvable nexthop | | [0x0016] | not preferred for Local preference | - | [0x0017] | not preferred for Weight | - | [0x0018] | not preferred for path to next hop with bit error | - | [0x0019] | not preferred for path id | - | [0x001A] | not preferred for ROV validation | - | [0x001B] | not preferred for originate IP | - | [0x001C] | not preferred for route distinguisher | - | [0x001D] | not preferred for delayed route selection | - | [0x001E] | not preferred for imported from other instances | - | [0x001F] | not preferred for med plus igp cost | + | [0x0014] | not preferred for AS Path Length | + | [0x0013] | not preferred for origin | + | [0x0012] | not preferred for MED | + | [0x0011] | not preferred for peer type | + | [0x0010] | not preferred for IGP cost | + | [0x000E] | not preferred for router ID | + | [0x000D] | not preferred for peer address | | [0x0020] | not preferred for AIGP | - | [0x0021] | not preferred for BGP LSP aigp for next hop relay | - | [0x0022] | not preferred for nexthop IP | +----------+-----------------------------------------------------+ Table 2: IANA-Registered Reason Code + Figure 2 + +2.2. Enterprise-specific Path Status TLV + -Cardona, et al. Expires April 22, 2023 [Page 5] - -Internet-Draft BMP path status tlv Oct 2022 -2.2. Enterprise-specific Path Status TLV + +Cardona, et al. Expires 11 September 2023 [Page 5] + +Internet-Draft BMP path status tlv March 2023 + 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 +-------------------------------+-------------------------------+ @@ -299,32 +297,33 @@ Internet-Draft BMP path status tlv Oct 2022 Figure 3: Encoding of Enterprise-specific Path Status TLV - o E bit: For an Enterprise-specific TLV, the E bit MUST be set to 1. + * E bit: For an Enterprise-specific TLV, the E bit MUST be set to 1 + [I-D.ietf-grow-bmp-tlv-ebit]. - o Type = 1 (15 Bits): indicates that it's the Enterprise-specific + * Type = 1 (15 Bits): indicates that it's the Enterprise-specific Path Status TLV. - o Length (2 Octets): indicates the length of the value field of the + * Length (2 Octets): indicates the length of the value field of the Path Status TLV. The value field further consists of the Path- Status field and Reason Code field. - o Index (2 Octets): indicates the prefix that this TLV is + * Index (2 Octets): indicates the prefix that this TLV is describing. The index is the encapsulation order, starting from 0, of the prefix in the BGP Update PDU. - o PEN Number (4 octets): indicates the IANA enterprise number IANA- + * PEN Number (4 octets): indicates the IANA enterprise number IANA- PEN. - o Path Status (4 Octets): indicates the enterprise-specific path + * Path Status (4 Octets): indicates the enterprise-specific path status. The format is to be determined w.r.t. each PEN number. - o Reason Code (2 octets, optional): indicates the reasons/ + * Reason Code (2 octets, optional): indicates the reasons/ explanations of the path status indicated in the Path Status field. The format is to be determined w.r.t. each PEN number. -3. Acknowledgments +3. Implementation notes - We would like to thank Jeff Haas for his valuable comments. + The BMP path marking TLV remains optional within BMP implementations. @@ -333,12 +332,100 @@ Internet-Draft BMP path status tlv Oct 2022 -Cardona, et al. Expires April 22, 2023 [Page 6] + +Cardona, et al. Expires 11 September 2023 [Page 6] -Internet-Draft BMP path status tlv Oct 2022 +Internet-Draft BMP path status tlv March 2023 + + + An implementation of the BMP path marking TLV may not fully support + marking of all status defined in table Figure 1 or any future + extensions. Similarly, an implementation may choose to support the + inclusion of the reason code (for which support is also optional), + without necessarily incorporating any of the reason codes defined in + table Figure 2 or future extensions. + + This document refrains from defining mechanisms for signaling the + status or reason codes an implementation supports. This could be + established through external means (e.g. documentation) or + potentially addressed in a subsequent document. + + The remainder of this section encompasses additional points related + to the implementation of the BMP Path marking TLV. + +3.1. Configuration of BMP path marking + + Implementations supporting the BMP path marking TLV SHOULD provide an + option for enabling or disabling the Path Marking TLV over BMP + sessions. Furthermore, the configuration options for this TLV SHOULD + provide the means to enable and disable the transmission of reason + codes, if the reason code are supported by the implementation. + +3.2. Paths with no markings + + Some BGP routes might not require any type of status or reasons. For + example, an unfiltered path obtained via the Adj-RIB-IN may fall + under this category since there is really nothing to mark for that + path. We suggest a couple of approaches for signaling that a path + has no markings: (1) An implicit form of marking, achieved by + abstaining from appending any BMP marking TLV pointing toward the + route. (2) Alternatively, an explicit marking of the packet through a + TLV containing no marked status and no associated reason code. + +3.3. Significance of status and origin RIBs + + This document refrains from imposing any implementation to mark + specific status from specific RIBs. We recognize the diversity among + implementations; some might be able to mark some status over one RIB + while other do it on others. For instance, some might be able to + mark Adj-RIB-in filtered routes when obtained from the Adj-RIB-IN + pre, while other could do it only from the Adj-RIB-IN post. To + remove ambiguities in implementations, we recommend the meaning of + status (and reason codes) to not depend on the origin RIB of a route. + + + + + + + +Cardona, et al. Expires 11 September 2023 [Page 7] + +Internet-Draft BMP path status tlv March 2023 + + +3.4. Enterprise-specific status and reasons + + Implementations introducing their own status and reason codes are + advised to adhere to [I-D.ietf-grow-bmp-tlv-ebit] and use ebit and + vendor specific status and reasons. Additionally, we recommend all + implementations to provide comprehensive documentation for these + codes. + For scenarios where a path state combines a standard status with an + enterprise-specific reason code (or vice versa), the following + alternatives are presented: -4. IANA Considerations + * Replication of the standard definitions within the enterprise- + specific space, thus permitting direct marking within the same + packet using the ebit. + * Assigning two TLVs to the same path(s): one containing the + standard part and another housing the vendor-specific part. + +3.5. Multiple TLVs assigned to the same route. + + We advocate for the employment of TLV grouping wherever feasible. + The inclusion of all marking information within a single message is + recommended, except on the case described in section Section 3.4. In + situations where multiple TLVs are associated with a single route, + all markings will be applicable to that route. + +4. Acknowledgments + + We would like to thank Jeff Haas and Maxence Younsi for their + valuable comments. + +5. IANA Considerations This document requests that IANA assign the following new parameters to the BMP parameters name space. @@ -346,60 +433,58 @@ Internet-Draft BMP path status tlv Oct 2022 Type = TBD1 (15 Bits): indicates that it is the IANA-registered Path Status TLV. -5. Security Considerations +6. Security Considerations It is not believed that this document adds any additional security considerations. -6. Normative References +7. Normative References + + + + + + +Cardona, et al. Expires 11 September 2023 [Page 8] + +Internet-Draft BMP path status tlv March 2023 + [I-D.ietf-grow-bmp-tlv] Lucente, P. and Y. Gu, "TLV support for BMP Route - Monitoring and Peer Down Messages", draft-ietf-grow-bmp- - tlv-08 (work in progress), October 2022, - . + Monitoring and Peer Down Messages", Work in Progress, + Internet-Draft, draft-ietf-grow-bmp-tlv-12, 27 March 2023, + . [I-D.ietf-grow-bmp-tlv-ebit] Lucente, P. and Y. Gu, "Support for Enterprise-specific - TLVs in the BGP Monitoring Protocol", draft-ietf-grow-bmp- - tlv-ebit-00 (work in progress), July 2022, - . + TLVs in the BGP Monitoring Protocol", Work in Progress, + Internet-Draft, draft-ietf-grow-bmp-tlv-ebit-03, 24 July + 2023, . [I-D.ietf-idr-best-external] Marques, P., Fernando, R., Chen, E., Mohapatra, P., and H. Gredler, "Advertisement of the best external route in - BGP", draft-ietf-idr-best-external-05 (work in progress), - January 2012, . + BGP", Work in Progress, Internet-Draft, draft-ietf-idr- + best-external-05, 3 January 2012, + . [I-D.ietf-rtgwg-bgp-pic] Bashandy, A., Filsfils, C., and P. Mohapatra, "BGP Prefix - Independent Convergence", draft-ietf-rtgwg-bgp-pic-18 - (work in progress), April 2022, - . - - - - - - - - - -Cardona, et al. Expires April 22, 2023 [Page 7] - -Internet-Draft BMP path status tlv Oct 2022 - + Independent Convergence", Work in Progress, Internet- + Draft, draft-ietf-rtgwg-bgp-pic-19, 1 April 2023, + . [I-D.lapukhov-bgp-ecmp-considerations] Lapukhov, P. and J. Tantsura, "Equal-Cost Multipath - Considerations for BGP", draft-lapukhov-bgp-ecmp- - considerations-09 (work in progress), July 2022, - . + Considerations for BGP", Work in Progress, Internet-Draft, + draft-lapukhov-bgp-ecmp-considerations-11, 26 June 2023, + . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, @@ -411,6 +496,16 @@ Internet-Draft BMP path status tlv Oct 2022 DOI 10.17487/RFC4271, January 2006, . + + + + + +Cardona, et al. Expires 11 September 2023 [Page 9] + +Internet-Draft BMP path status tlv March 2023 + + [RFC7854] Scudder, J., Ed., Fernando, R., and S. Stuart, "BGP Monitoring Protocol (BMP)", RFC 7854, DOI 10.17487/RFC7854, June 2016, @@ -430,32 +525,16 @@ Authors' Addresses Camilo Cardona NTT 164-168, Carrer de Numancia - Barcelona 08029 + 08029 Barcelona Spain - Email: camilo@ntt.net - - - - - - - - - -Cardona, et al. Expires April 22, 2023 [Page 8] - -Internet-Draft BMP path status tlv Oct 2022 - - Paolo Lucente NTT Siriusdreef 70-72 - Hoofddorp, WT 2132 + 2132 Hoofddorp Netherlands - Email: paolo@ntt.net @@ -463,25 +542,31 @@ Internet-Draft BMP path status tlv Oct 2022 INSA-Lyon Lyon France - Email: Pierre.Francois@insa-lyon.fr Yunan Gu Huawei Huawei Bld., No.156 Beiqing Rd. - Beijing 100095 + Beijing + 100095 China - Email: guyunan@huawei.com + + + +Cardona, et al. Expires 11 September 2023 [Page 10] + +Internet-Draft BMP path status tlv March 2023 + + Thomas Graf Swisscom Binzring 17 - Zurich 8045 + CH-8045 Zurich Switzerland - Email: thomas.graf@swisscom.com @@ -501,4 +586,31 @@ Internet-Draft BMP path status tlv Oct 2022 -Cardona, et al. Expires April 22, 2023 [Page 9] + + + + + + + + + + + + + + + + + + + + + + + + + + + +Cardona, et al. Expires 11 September 2023 [Page 11] diff --git a/draft-cppy-grow-bmp-path-marking-tlv.xml b/draft-cppy-grow-bmp-path-marking-tlv.xml index 217df81..e3f45c4 100644 --- a/draft-cppy-grow-bmp-path-marking-tlv.xml +++ b/draft-cppy-grow-bmp-path-marking-tlv.xml @@ -1,5 +1,4 @@ - @@ -10,7 +9,7 @@ - BMP Extension for Path Status @@ -114,7 +113,7 @@ </address> </author> - <date day="19" month="Oct" year="2022"/> + <date day="10" month="Mar" year="2023"/> <abstract> <t>The BGP Monitoring Protocol (BMP) provides an interface for obtaining @@ -183,7 +182,7 @@ Figure 2: Encoding of IANA-Registered Path Status TLV ]]></artwork> </figure><list style="symbols"> <t>E bit: For an IANA-registered TLV, the E bit MUST be set to - 0.</t> + 0 <xref target="I-D.ietf-grow-bmp-tlv-ebit"/>.</t> <t>Type = TBD2 (15 Bits): indicates that it is the IANA-registered Path Status TLV.</t> @@ -193,8 +192,9 @@ Path-Status field and Reason Code field.</t> <t>Index (2 Octets): indicates the prefix that this TLV is describing. - The index is the encapsulation order, starting from 0, of the - prefix in the BGP Update PDU.</t> + Please see <xref target="I-D.ietf-grow-bmp-tlv"/> for details of + the use of the index field to associate the path marking content with one or + more NLRIs.</t> <t>Path Status (4 Octets): indicates the path status of the BGP Update PDU encapsulated in the RM Message. Currently 10 types of @@ -206,11 +206,10 @@ code field is optional. If no reason code is carried, this field is empty. If a reason code is carried, the reason code is indicated by a 2-byte value, which is defined in Table 2.</t> - </list><figure> + </list><figure anchor="status_codes"> <artwork align="center"><![CDATA[+------------+-----------------------------+ | Value | Path type | +------------------------------------------+ -| 0x00000000 | Reserved | | 0x00000001 | Invalid | | 0x00000002 | Best | | 0x00000004 | Non-selected | @@ -264,47 +263,25 @@ Table 1: IANA-Registered Path Type ]]></artwork> </list> - The path status TLV does not force a BMP client to send any - of these paths. It just provides a method to mark the paths that - are available with their status. + The path status TLV does not force a BMP client to send any of + these paths. It just provides a method to mark the paths that are + available with their status. -<figure> +<figure anchor="reasons_codes"> <artwork align="center"><![CDATA[+----------+-----------------------------------------------------+ | Value | Reason code | +----------------------------------------------------------------+ -| [0x0001] | invalid for super network | -| [0x0002] | invalid for dampening | -| [0x0003] | invalid for damping history | -| [0x0005] | invalid for ROV not valid | -| [0x0006] | invalid for interface error | -| [0x0007] | invalid for nexthop route unreachable | -| [0x0008] | invalid for nexthop tunnel unreachable | -| [0x0009] | invalid for nexthop restrain | -| [0x000A] | invalid for not supporting BGP LSP relay | -| [0x000B] | invalid for being inactive within VPN insance | -| [0x000C] | invalid for prefix sid not exist | -| [0x000D] | not preferred for peer address | -| [0x000E] | not preferred for router ID | -| [0x000F] | not preferred for Cluster List | -| [0x0010] | not preferred for IGP cost | -| [0x0011] | not preferred for peer type | -| [0x0012] | not preferred for MED | -| [0x0013] | not preferred for origin | -| [0x0014] | not preferred for AS Path | -| [0x0015] | not preferred for route type | +| [0x0007] | invalid for AS loop | +| [0x0007] | invalid for unresolvable nexthop | | [0x0016] | not preferred for Local preference | -| [0x0017] | not preferred for Weight | -| [0x0018] | not preferred for path to next hop with bit error | -| [0x0019] | not preferred for path id | -| [0x001A] | not preferred for ROV validation | -| [0x001B] | not preferred for originate IP | -| [0x001C] | not preferred for route distinguisher | -| [0x001D] | not preferred for delayed route selection | -| [0x001E] | not preferred for imported from other instances | -| [0x001F] | not preferred for med plus igp cost | +| [0x0014] | not preferred for AS Path Length | +| [0x0013] | not preferred for origin | +| [0x0012] | not preferred for MED | +| [0x0011] | not preferred for peer type | +| [0x0010] | not preferred for IGP cost | +| [0x000E] | not preferred for router ID | +| [0x000D] | not preferred for peer address | | [0x0020] | not preferred for AIGP | -| [0x0021] | not preferred for BGP LSP aigp for next hop relay | -| [0x0022] | not preferred for nexthop IP | +----------+-----------------------------------------------------+ Table 2: IANA-Registered Reason Code ]]></artwork> @@ -329,7 +306,7 @@ Table 1: IANA-Registered Path Type ]]></artwork> Figure 3: Encoding of Enterprise-specific Path Status TLV]]></artwork> </figure><list style="symbols"> <t>E bit: For an Enterprise-specific TLV, the E bit MUST be set to - 1.</t> + 1 <xref target="I-D.ietf-grow-bmp-tlv-ebit"/>.</t> <t>Type = 1 (15 Bits): indicates that it's the Enterprise-specific Path Status TLV.</t> @@ -355,8 +332,106 @@ Table 1: IANA-Registered Path Type ]]></artwork> </section> </section> + <section title="Implementation notes"> + + <t>The BMP path marking TLV remains optional within BMP + implementations.</t> + + <t>An implementation of the BMP path marking TLV may not fully support + marking of all status defined in table <xref target="status_codes"/> or + any future extensions. Similarly, an implementation may choose to + support the inclusion of the reason code (for which support is also + optional), without necessarily incorporating any of the reason codes + defined in table <xref target="reasons_codes"/> or future + extensions.</t> + + <t>This document refrains from defining mechanisms for signaling the + status or reason codes an implementation supports. This could be + established through external means (e.g. documentation) or + potentially addressed in a subsequent document.</t> + + <t>The remainder of this section encompasses additional points related + to the implementation of the BMP Path marking TLV.</t> + + <section title="Configuration of BMP path marking"> + + <t>Implementations supporting the BMP path marking TLV SHOULD + provide an option for enabling or disabling the Path Marking + TLV over BMP sessions. Furthermore, the configuration options + for this TLV SHOULD provide the means to enable and disable the + transmission of reason codes, if the reason code are supported by the + implementation.</t> + + </section> + + <section title="Paths with no markings"> + + <t>Some BGP routes might not require any type of status or reasons. + For example, an unfiltered path obtained via the Adj-RIB-IN may + fall under this category since there is really nothing to mark for + that path. We suggest a couple of approaches for signaling + that a path has no markings: (1) An implicit form of marking, + achieved by abstaining from appending any BMP marking TLV pointing + toward the route. (2) Alternatively, an explicit marking of the + packet through a TLV containing no marked status and no associated + reason code.</t> + + </section> + + <section title="Significance of status and origin RIBs"> + + <t>This document refrains from imposing any implementation to mark + specific status from specific RIBs. We recognize the diversity + among implementations; some might be able to mark some status over + one RIB while other do it on others. For instance, some might be + able to mark Adj-RIB-in filtered routes when obtained from the + Adj-RIB-IN pre, while other could do it only from the Adj-RIB-IN + post. To remove ambiguities in implementations, we recommend the + meaning of status (and reason codes) to not depend on the + origin RIB of a route.</t> + + </section> + + <section title="Enterprise-specific status and reasons" anchor="ebit_mixed"> + + <t>Implementations introducing their own status and reason codes + are advised to adhere to <xref + target="I-D.ietf-grow-bmp-tlv-ebit"/> and use ebit and vendor + specific status and reasons. Additionally, we recommend all + implementations to provide comprehensive documentation for + these codes.</t> + + <t>For scenarios where a path state combines a standard status with + an enterprise-specific reason code (or vice versa), the + following alternatives are presented:</t> + + <t> + <ul spacing="compact"> + <li>Replication of the standard + definitions within the enterprise-specific space, thus permitting + direct marking within the same packet using the ebit.</li> + <li>Assigning two TLVs to the same path(s): one containing the standard + part and another housing the vendor-specific part.</li> + </ul> + </t> + + </section> + + <section title="Multiple TLVs assigned to the same route."> + + <t>We advocate for the employment of TLV grouping wherever + feasible. The inclusion of all marking information within a + single message is recommended, except on the case described in + section <xref target="ebit_mixed"/>. In situations where + multiple TLVs are associated with a single route, all + markings will be applicable to that route.</t> + + </section> + </section> + <section title="Acknowledgments"> - <t>We would like to thank Jeff Haas for his valuable comments.</t> + <t>We would like to thank Jeff Haas and Maxence Younsi for their + valuable comments.</t> </section> <section anchor="IANA" title="IANA Considerations"> @@ -375,25 +450,25 @@ Table 1: IANA-Registered Path Type ]]></artwork> <back> <references title="Normative References"> - <?rfc include="reference.RFC.2119"?> + <?rfc include="reference.RFC.2119.xml"?> - <?rfc include="reference.RFC.8174"?> + <?rfc include="reference.RFC.8174.xml"?> - <?rfc include='reference.RFC.4271'?> + <?rfc include='reference.RFC.4271.xml'?> - <?rfc include='reference.RFC.7854'?> + <?rfc include='reference.RFC.7854.xml'?> - <?rfc include='reference.I-D.ietf-idr-best-external'?> + <?rfc include='reference.I-D.ietf-idr-best-external.xml'?> - <?rfc include='reference.I-D.ietf-grow-bmp-tlv'?> + <?rfc include='reference.I-D.ietf-grow-bmp-tlv.xml'?> - <?rfc include='reference.I-D.ietf-rtgwg-bgp-pic'?> + <?rfc include='reference.I-D.ietf-rtgwg-bgp-pic.xml'?> - <?rfc include='reference.I-D.lapukhov-bgp-ecmp-considerations'?> + <?rfc include='reference.I-D.lapukhov-bgp-ecmp-considerations.xml'?> - <?rfc include='reference.RFC.7911'?> + <?rfc include='reference.RFC.7911.xml'?> - <?rfc include='reference.I-D.ietf-grow-bmp-tlv-ebit'?> + <?rfc include='reference.I-D.ietf-grow-bmp-tlv-ebit.xml'?> </references> </back> </rfc>