9. 参考文献 (References)
本节列出 RFC 9929 使用的规范性和资料性参考文献. 规范性参考文献定义了 IS-IS、OSPFv2、OSPFv3、OSPF NSSA、OSPF/IS-IS 安全扩展、multi-topology IS-IS、IS-IS traffic engineering、IPv6 over IS-IS、OSPF stub router、prefix/link attributes、SRv6、Flexible Algorithm、OSPFv3 SRv6 和 prefix flag 扩展等基础规则. 这些文献直接约束 UPA 的编码、flag 位置、metric 语义、传播行为和安全处理.
资料性参考文献中的 BGP-PIC 草案用于说明 UPA 的一个重要动机: 当 IGP summarization 隐藏单个前缀状态时, 外部快速收敛机制可能需要明确的不可达信号来更快选择替代路径. 文献条目中的作者、英文标题、RFC 编号、DOI、Internet-Draft 名称和 URL 保持原文, 以便准确检索和核对.
阅读本节时, 可按协议族分组: IS-IS 相关文献说明高 metric、prefix attributes、SRv6 locator 和 L1/L2 传播语义; OSPF 相关文献说明 OSPFv2/OSPFv3 的 prefix flags、LSA 扩展和维护状态; 安全文献说明如何降低伪造 UPA 的风险. 中文说明不替代原文规范, 只帮助读者理解引用关系.
对于实现者来说, 本节也是排查互操作问题的索引. 如果问题出在 IS-IS U-Flag 或 UP-Flag 编码, 应查 RFC 7794 和相关 IS-IS TLV 文献; 如果问题出在 OSPF prefix extended flags, 应查 RFC 7684、RFC 8362 和 RFC 9792; 如果问题出在计划维护或高 metric 语义, 应回到 OSPF stub router、host router support 和基础 IGP 规范核对行为.
由于 UPA 横跨 IS-IS、OSPFv2 和 OSPFv3, 本节中的引用共同保证同一语义在不同 IGP 中有可比较的表达方式. 保留完整英文书目信息可以帮助实现者确认自己引用的是正确版本, 特别是较新的 SRv6、Flexible Algorithm 和 prefix flag 扩展文献.
本节中的 BGP-PIC 虽然是资料性引用, 但有助于解释 UPA 被消费的典型场景: 接收方可以把不可达前缀事件作为快速收敛输入. 规范性引用则负责定义 UPA 信令如何安全、可互操作地出现在各 IGP 的既有扩展点中. 因此, 阅读时应区分"为什么需要 UPA"和"如何编码 UPA"这两个层次.
在维护实现或排查部署差异时, 建议先确认使用的是哪个 IGP 和哪个地址族, 再回到相应参考文献核对字段位置、泛洪范围和兼容性规则. 对 SRv6 或 Flexible Algorithm 场景, 还需要同时查看较新的扩展 RFC, 因为 UPA 信号可能与 locator、algorithm 或 prefix attribute 的解释共同决定最终转发表行为.
9. References
9.1. Normative References
[ISO10589] ISO/IEC, "Information technology -- Telecommunications and
information exchange between systems -- Intermediate
System to Intermediate System intra-domain routeing
information exchange protocol for use in conjunction with
the protocol for providing the connectionless-mode network
service (ISO 8473)", ISO/IEC 10589:2002, November 2002,
<https://www.iso.org/en/contents/data/
standard/03/09/30932.html>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328,
DOI 10.17487/RFC2328, April 1998,
<https://www.rfc-editor.org/info/rfc2328>.
[RFC3101] Murphy, P., "The OSPF Not-So-Stubby Area (NSSA) Option",
RFC 3101, DOI 10.17487/RFC3101, January 2003,
<https://www.rfc-editor.org/info/rfc3101>.
[RFC4552] Gupta, M. and N. Melam, "Authentication/Confidentiality
for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006,
<https://www.rfc-editor.org/info/rfc4552>.
[RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
Topology (MT) Routing in Intermediate System to
Intermediate Systems (IS-ISs)", RFC 5120,
DOI 10.17487/RFC5120, February 2008,
<https://www.rfc-editor.org/info/rfc5120>.
[RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic
Authentication", RFC 5304, DOI 10.17487/RFC5304, October
2008, <https://www.rfc-editor.org/info/rfc5304>.
[RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic
Engineering", RFC 5305, DOI 10.17487/RFC5305, October
2008, <https://www.rfc-editor.org/info/rfc5305>.
[RFC5308] Hopps, C., "Routing IPv6 with IS-IS", RFC 5308,
DOI 10.17487/RFC5308, October 2008,
<https://www.rfc-editor.org/info/rfc5308>.
[RFC5310] Bhatia, M., Manral, V., Li, T., Atkinson, R., White, R.,
and M. Fanto, "IS-IS Generic Cryptographic
Authentication", RFC 5310, DOI 10.17487/RFC5310, February
2009, <https://www.rfc-editor.org/info/rfc5310>.
[RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008,
<https://www.rfc-editor.org/info/rfc5340>.
[RFC6987] Retana, A., Nguyen, L., Zinin, A., White, R., and D.
McPherson, "OSPF Stub Router Advertisement", RFC 6987,
DOI 10.17487/RFC6987, September 2013,
<https://www.rfc-editor.org/info/rfc6987>.
[RFC7370] Ginsberg, L., "Updates to the IS-IS TLV Codepoints
Registry", RFC 7370, DOI 10.17487/RFC7370, September 2014,
<https://www.rfc-editor.org/info/rfc7370>.
[RFC7474] Bhatia, M., Hartman, S., Zhang, D., and A. Lindem, Ed.,
"Security Extension for OSPFv2 When Using Manual Key
Management", RFC 7474, DOI 10.17487/RFC7474, April 2015,
<https://www.rfc-editor.org/info/rfc7474>.
[RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W.,
Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute
Advertisement", RFC 7684, DOI 10.17487/RFC7684, November
2015, <https://www.rfc-editor.org/info/rfc7684>.
[RFC7794] Ginsberg, L., Ed., Decraene, B., Previdi, S., Xu, X., and
U. Chunduri, "IS-IS Prefix Attributes for Extended IPv4
and IPv6 Reachability", RFC 7794, DOI 10.17487/RFC7794,
March 2016, <https://www.rfc-editor.org/info/rfc7794>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and
F. Baker, "OSPFv3 Link State Advertisement (LSA)
Extensibility", RFC 8362, DOI 10.17487/RFC8362, April
2018, <https://www.rfc-editor.org/info/rfc8362>.
[RFC8770] Patel, K., Pillay-Esnault, P., Bhardwaj, M., and S.
Bayraktar, "Host Router Support for OSPFv2", RFC 8770,
DOI 10.17487/RFC8770, April 2020,
<https://www.rfc-editor.org/info/rfc8770>.
[RFC9352] Psenak, P., Ed., Filsfils, C., Bashandy, A., Decraene, B.,
and Z. Hu, "IS-IS Extensions to Support Segment Routing
over the IPv6 Data Plane", RFC 9352, DOI 10.17487/RFC9352,
February 2023, <https://www.rfc-editor.org/info/rfc9352>.
[RFC9502] Britto, W., Hegde, S., Kaneriya, P., Shetty, R., Bonica,
R., and P. Psenak, "IGP Flexible Algorithm in IP
Networks", RFC 9502, DOI 10.17487/RFC9502, November 2023,
<https://www.rfc-editor.org/info/rfc9502>.
[RFC9513] Li, Z., Hu, Z., Talaulikar, K., Ed., and P. Psenak,
"OSPFv3 Extensions for Segment Routing over IPv6 (SRv6)",
RFC 9513, DOI 10.17487/RFC9513, December 2023,
<https://www.rfc-editor.org/info/rfc9513>.
[RFC9792] Chen, R., Zhao, D., Psenak, P., Talaulikar, K., and L.
Gong, "Prefix Flag Extension for OSPFv2 and OSPFv3",
RFC 9792, DOI 10.17487/RFC9792, June 2025,
<https://www.rfc-editor.org/info/rfc9792>.
9.2. Informative References
[BGP-PIC] Bashandy, A., Ed., Filsfils, C., Mohapatra, P., and Y. Qu,
"BGP Prefix Independent Convergence", Work in Progress,
Internet-Draft, draft-ietf-rtgwg-bgp-pic-23, 15 February
2026, <https://datatracker.ietf.org/doc/html/draft-ietf-
rtgwg-bgp-pic-23>.