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RFC 9869 - Datagram Packetization Layer Path MTU Discovery (DPLPMTUD) for UDP Options

  • Status: Proposed Standard
  • Published: October 2025
  • Stream: IETF
  • Pages: 13
  • Errata: No Errata

Abstract

This document specifies how a UDP Options sender implements Datagram Packetization Layer Path MTU Discovery (DPLPMTUD) as a robust method for Path MTU Discovery (PMTUD). The method uses the UDP Options packetization layer, allowing an application to discover the largest datagram size that can be sent across a network path and to periodically verify the current Maximum Packet Size (MPS).