Loopback addresses let a process communicate through its local IP stack without sending the exchange over a physical network link. IPv4 reserves 127.0.0.0/8 for loopback; 127.0.0.1 is the familiar member. IPv6 uses ::1. On Linux, the relevant local networking context is a network namespace. Two processes on the same physical machine can therefore have different answers to what counts as their own loopback service. ...
Verify the artifact before replacing the live directory, and keep the checks close to the release command.
One aggregate digest is useful, but a sorted per-file manifest tells you exactly what changed or went missing.
Validate one staged artifact, publish it, then compare representative public responses with those exact bytes.
A 206 response is useful only when its boundaries and total size describe the bytes that were returned.
HEAD is a metadata view of GET; status and representation headers should tell the same story.