Constrained Application Protocol (CoAP): Echo, Request-Tag, and Token Processing
RFC 9175

Received changes through RFC Editor sync (created alias RFC 9175, changed title to 'Constrained Application Protocol (CoAP): Echo, Request-Tag, and Token Processing', changed abstract to 'This document specifies enhancements to the Constrained Application Protocol (CoAP) that mitigate security issues in particular use cases.  The Echo option enables a CoAP server to verify the freshness of a request or to force a client to demonstrate reachability at its claimed network address.  The Request-Tag option allows the CoAP server to match block-wise message fragments belonging to the same request.  This document updates RFC 7252 with respect to the following: processing requirements for client Tokens, forbidding non-secure reuse of Tokens to ensure response-to-request binding when CoAP is used with a security protocol, and amplification mitigation (where the use of the Echo option is now recommended).', changed pages to 27, changed standardization level to Proposed Standard, changed state to RFC, added RFC published event at 2022-02-24, changed IESG state to RFC Published, created updates relation between draft-ietf-core-echo-request-tag and RFC 7252)