Function is_known_cloud_metadata_endpoint 

pub fn is_known_cloud_metadata_endpoint(ip: IpAddr) -> bool

True when ip is a provider-documented metadata endpoint, rather than another address in the metadata-sensitive IPv4 link-local range.

is_cloud_metadata_ip intentionally blocks all of 169.254.0.0/16. This narrower classifier exists only so diagnostics can distinguish known metadata endpoints from ordinary APIPA/link-local addresses without weakening that unconditional block. Recognized IPv4-embedded forms receive the same classification as their effective IPv4 destination.