The IESG has approved the following document: - 'Revised Error Handling for BGP UPDATE Messages' (draft-ietf-idr-error-handling-19.txt) as Proposed Standard This document is the product of the Inter-Domain Routing Working Group. The IESG contact persons are Alvaro Retana, Alia Atlas and Deborah Brungard. A URL of this Internet Draft is: https://datatracker.ietf.org/doc/draft-ietf-idr-error-handling/ Technical Summary The document describes revisions to the error handling behavior that is defined in the base BGP-4 specification (RFC4271). The motivation for changes to this behaviour is to avoid a single erroneous UPDATE message (or attribute within such a message) impacting an entire BGP-4 session (and hence all the NLRI that it carries). The document introduces the "treat-as-withdraw" mechanism, which treats the NLRI received within an erroneous UPDATE message as though they are withdrawn by the remote neighbor. Additionally an "attribute discard" approach is introduced. The document evaluates the existing BGP-4 attributes and defines new error handling behaviours for them. Errors for which the existing BGP-4 error handling behaviour is to be retained are also considered. There is working group consensus amongst both network operators, and BGP-4 implementors that this mechanism is a useful Standards Track document to improve the robustness of the BGP-4 protocol, whilst also considering the correctness of routing information it carries. Working Group Summary There has been significant debate relating to the balance of different functionalities required between working group participants which seek to maintain established sessions (or retain NLRI during their failure), and those that consider the correctness of the protocol paramount. The document's intention was originally to address a point failure scenario observed within the Internet related to optional transitive attributes, but based on wider operational experience, the working group has extended the scope of the document. Document Quality The behaviours now included within the document have been subject to significant review over multiple cycles from both protocol experts, network operators, and protocol implementors contributing to the balance between approaches having been reached. Operational requirements for the changes within the document have been discussed at length - and reviewed with GROW. Whilst there is some appetite for additional mechanisms for operators to maintain the integrity of their networks by compromising correctness of the routing information in their network - especially during catastrophic failures - this document does not reflect these additional requirements - which are subject to separate proposals to the working group. Significant deployment experience has been gained for the changes described in the document. The shepherd is aware of four shipping commercial implementations of BGP-4 (Alcatel-Lucent SR OS, Cisco IOS, Cisco IOS XR, Juniper JUNOS), and one open source implementation (Quagga) have implemented the behaviours described in the document. The feedback from these implementations has helped to iterate the contents of the document, and reach consensus within the working group. Status of administrative actions: Public IPR Call: 11/12 to 11/19/14 Routing Directorate Review status: Joel Halpern (11/18), QA review completed (9/4) OPS Directorate status: Reviewer: Warren Kumari (11/16) done Gen-Art Pre-review: Pending, 10/14 IANA: No early review Personnel The document shepherd is Rob Shakir. The WG Chair responsible: Sue Hares [John Scudder is co-author] The responsible Area Director is Alvaro Retana.
