Telechat Review of draft-ietf-dnsop-dns-error-reporting-07
review-ietf-dnsop-dns-error-reporting-07-tsvart-telechat-fairhurst-2023-12-07-00
review-ietf-dnsop-dns-error-reporting-07-tsvart-telechat-fairhurst-2023-12-07-00
This document has been reviewed as part of the transport area review team's ongoing effort to review key IETF documents. These comments were written primarily for the transport area directors, but are copied to the document's authors and WG to allow them to address any issues raised and also to the IETF discussion list for information. When done at the time of IETF Last Call, the authors should consider this review as part of the last-call comments they receive. Please always CC tsv-art@ietf.org if you reply to or forward this review. Thank you for a well written document, and it's description of the service to be provided. This is proposed as a "lightweight" reporting mechanism. The method states it can be used over TCP. In this case, TCP provides the necessary congestion control, flow control and segmentation. I did not see additional transport concerns. Thius is an updated review for -07, which addressed some of the previous issues. The method also states it can be used over UDP - which is equally recommended. However, the specification for use over UDP is incomplete and raises some transport concerns: 1. There is a recommendation to use DNS COOKIEs [RFC7873] over UDP (PS), but no statement about how to mitigate the effects when these are not used. What ought someone to do when this is not done? 2. New text was added to note how to handle reports larger than the maximum UDP datagram payload. (This is likely resolved in -07.) 3. I think this method could in some uses generate a stream of reports at a rate that could be more than a few UDP datagrams per RTT, (e.g., if implementing automated responses). In this case, I think method would need to provide some basic rate-limiting (or implement a form of congestion control). I understand the rate is usually "damped" by caching to one message/TTL perreport, but I am unsure whether this is sufficient to mitigate any congestion control concerns. Additional text may still be needed.