Hi Chairs, Authors, and GROW WG, I support the WG adoption of draft-spaghetti-grow-downgrade-bgp-community-00.
The draft addresses a very practical operational issue in DDoS mitigation. Providing a standardized signal to lower the precedence of traffic—rather than dropping it entirely via Remote Triggered Blackhole (RTBH)—gives operators a valuable, less destructive tool in their mitigation toolbox. I have one constructive suggestion for the authors to consider as the document progresses in the working group: Clarify the explicit impact on the BGP Decision Process Currently, the draft focuses heavily on the traffic management outcome (lowering traffic precedence/scrubbing), but it could benefit from a more explicit description of how the DOWNGRADE community affects the control plane, specifically the BGP Best Path Selection algorithm. To ensure predictable behavior across vendors and implementations, it would be helpful to explicitly specify in a dedicated section (e.g., Operational / Decision Process Impact): That a BGP speaker, upon evaluating candidate paths, MUST/SHOULD prefer a path NOT tagged with the DOWNGRADE community over a path tagged with it, provided other path attributes are equal. How this is typically realized in operational environments (e.g., automatically lowering LOCAL_PREF upon import policy execution, or inserting a decision step prior to LOCAL_PREF/MED comparisons). Adding this explicit control-plane tie-in will make the specification more normative and enhance multi-vendor interoperability. Thanks to the authors for bringing this work forward. Best regards, Shunwan -----Original Message----- From: Paolo Lucente via Datatracker <[email protected]> Sent: Wednesday, September 2, 2026 7:50 AM To: [email protected]; [email protected]; [email protected] Subject: [GROW] Call for adoption: draft-spaghetti-grow-downgrade-bgp-community-00 (Ends 2026-09-18) This message starts a grow WG Call for Adoption of: draft-spaghetti-grow-downgrade-bgp-community-00 This Working Group Call for Adoption ends on 2026-09-18 Abstract: This document outlines a method to mitigate Denial of Service (DoS) attacks by using a well-known BGP community named "DOWNGRADE" as signal to neighboring networks to treat traffic destined towards "DOWNGRADE" tagged IP prefixes with low precedence. The "downgrade" strategy offers an appealing alternative to Remote Triggered Blackhole (RTBH) filtering, because RTBH filtering completes the DoS attack and hampers the defender's ability to monitor whether the attack is still ongoing. Please reply to this message and indicate whether or not you support adoption of this Internet-Draft by the grow WG. Comments to explain your preference are greatly appreciated. Please reply to all recipients of this message and include this message in your response. Authors, and WG participants in general, are reminded of the Intellectual Property Rights (IPR) disclosure obligations described in BCP 79 [2]. Appropriate IPR disclosures required for full conformance with the provisions of BCP 78 [1] and BCP 79 [2] must be filed, if you are aware of any. Sanctions available for application to violators of IETF IPR Policy can be found at [3]. Thank you. [1] https://datatracker.ietf.org/doc/bcp78/ [2] https://datatracker.ietf.org/doc/bcp79/ [3] https://datatracker.ietf.org/doc/rfc6701/ The IETF datatracker status page for this Internet-Draft is: https://datatracker.ietf.org/doc/draft-spaghetti-grow-downgrade-bgp-community/ There is also an HTML version available at: https://www.ietf.org/archive/id/draft-spaghetti-grow-downgrade-bgp-community-00.html _______________________________________________ GROW mailing list -- [email protected] To unsubscribe send an email to [email protected] _______________________________________________ GROW mailing list -- [email protected] To unsubscribe send an email to [email protected]
