What happened
On 28 October 2026 draft-jakab-dawn-agent-discovery-mdns was updated to revision -01 (last updated 2026-10-28) by L. Jakab and F. Brockners (Cisco). It describes how the widely deployed Multicast DNS (mDNS) and DNS-Based Service Discovery (DNS-SD) protocols can be used to advertise and discover AI agents on a local link with no new protocol machinery. It presents a general, protocol-independent two-stage discovery model (lightweight enumeration over DNS-SD, then obtaining full agent metadata over the agent's native transport) and gives worked instantiations for the Agent2Agent (A2A) protocol and the Model Context Protocol (MCP), including TXT/SVCB record mappings and service-instance-name encoding.
Why it matters
It defines a zero-configuration discovery surface for local AI agents, enlarging the attack surface (agents become enumerable on local networks and expose metadata in TXT/SVCB records) and providing the discovery layer that agent identity and authentication must be designed against in the agentic ecosystem and the new agentproto work.
Action needed
Review the discovery metadata (TXT/SVCB records) for information leakage and spoofing risk; assess how local-link agent discovery interacts with agent authentication/authorization before relying on it in deployments.