F21-YG: Yes
Rationale
For applications on the Yggdrasil node itself, the native IPv6 source represents a cryptographic node identity. Ironwood authenticates session keys and decrypts traffic before returning the source key; ipv6rwc checks the IPv6 source against the address derived from that key before delivery. The application receives this checked address through ordinary UDP receive metadata. No application login is required for node identity.
Assessment method
Documentary/code analysis
Source context
Primary specification and receiving implementation
Outstanding qualification
Code trace with Ironwood d50055b11f5ec5b56ee4e56ba9a75261461821dc, not executed socket qualification. Test source mismatch, invalid handshake/traffic, rekey, restart and receive-interface provenance. The routed subnet alternative authenticates its owning router, not individual devices behind it. A process/user on the node is not separately identified; trusted local OS and interface isolation are assumed.