Function parse_nat64_prefixes 

pub fn parse_nat64_prefixes(
    prefixes: &[String],
    label: &str,
) -> Result<Vec<Nat64Prefix>>

Parse a whole operator-authored NAT64 prefix list, sorted and deduplicated.

label names the configuration surface in the error message so the operator can find the offending entry (for example "security.nat64_prefixes").

Errors

Returns an error naming every rejected entry, with the reason it was rejected, when one or more entries fail Nat64Prefix::parse.

A malformed list is never silently reduced to its well-formed subset. One bad entry rejects the whole list so that a typo fails the caller closed instead of quietly narrowing the validation boundary — a list that parsed to “no prefixes” would look exactly like a deployment that runs no NAT64 translator, and would disable network-specific classification without any signal.