Hi, I have been selected as the Operational Directorate (opsdir) reviewer for this Internet-Draft. The Operational Directorate reviews all operational and management-related Internet-Drafts to ensure alignment with operational best practices and that adequate operational considerations are covered. A complete set of _"Guidelines for Considering Operations and Management in IETF Specifications"_ can be found at https://datatracker.ietf.org/doc/draft-ietf-opsawg-rfc5706bis/. While these comments are primarily for the Operations and Management Area Directors (Ops ADs), the authors should consider them alongside other feedback received. - Document: draft-ietf-idr-bgpls-inter-as-topology-ext-27 - Reviewer: Tina Tsou - Review Date: 4/29/2026 - Intended Status: Standards Track --- ## Summary Choose one: - Has Nits: This document is basically ready for publication but has nits that should be considered prior to publication. This document extends BGP-LS to support inter-AS topology dissemination. The technical approach is sound and consistent with existing BGP-LS mechanisms. However, several operational aspects require clarification to ensure safe and scalable deployment across administrative domains. Key Operational Risks - Inter-AS Information Leakage Without clear scoping and policy guidance, topology information may unintentionally propagate beyond intended administrative boundaries. - Scaling and Control-Plane Load Inter-AS topology exchange can significantly increase state and churn, especially in large multi-domain deployments. - Troubleshooting Complexity Lack of guidance on debugging inconsistent or partial topology views across ASes may complicate fault isolation. - Policy Interaction Ambiguity Interaction with existing BGP policy controls (filtering, route selection, export policies) is not clearly defined. Missing Operational Considerations - No clear deployment models (e.g., controller-based vs. distributed, inter-provider scenarios) - Limited discussion of configuration controls (enable/disable, scoping, filtering) - No guidance on validation and verification of topology correctness - Insufficient detail on incremental deployment / backward compatibility - Minimal coverage of monitoring and telemetry expectations Recommended Changes (Top 5) 1. Add Deployment Scenarios Include at least one informative section describing typical inter-AS deployment models and operator workflows. 2. Define Policy and Scope Controls Clarify how operators can restrict, filter, or scope inter-AS topology advertisements to avoid unintended exposure. 3. Enhance Troubleshooting Guidance Provide operational guidance for detecting and resolving inconsistencies (e.g., missing links, mismatched topology views). 4. Address Scaling Considerations Add discussion of expected control-plane impact, including state growth and update frequency in large-scale deployments. 5. Describe Incremental Deployment Strategy Explain how these extensions can be deployed gradually across AS boundaries without requiring full network upgrades. Major Issues No major issues found. Minor Issues - Clarify terminology consistency (AS vs. domain vs. administrative boundary) - Add brief operational context to key encoding sections - Expand discussion on interaction with existing BGP policies Nits - Consider adding an example end-to-end inter-AS topology use case - Minor editorial improvements for clarity and readability Overall, this is a solid and useful extension to BGP-LS. Addressing the above points would improve operational clarity and deployability. Best regards, Tina Tsou