Enum CacheUsage

pub enum CacheUsage {
    NonRecursive,
    NxDomain,
    Loopback,
    Normal,
}

Caching DNS Servers:

Are developers of caching domain name servers expected to make their implementations recognize these names as special and treat them differently? If so, how?

Variants

NonRecursive

Caching DNS servers SHOULD recognize these names as special and SHOULD NOT, by default, attempt to look up NS records for them, or otherwise query authoritative DNS servers in an attempt to resolve these names. Instead, caching DNS servers SHOULD, by default, generate immediate (positive or negative) responses for all such queries. This is to avoid unnecessary load on the root name servers and other name servers. Caching DNS servers SHOULD offer a configuration option (disabled by default) to enable upstream resolution of such names, for use in private networks where private-address reverse-mapping names are known to be handled by an authoritative DNS server in said private network.

NxDomain

Caching DNS servers SHOULD recognize “invalid” names as special and SHOULD NOT attempt to look up NS records for them, or otherwise query authoritative DNS servers in an attempt to resolve “invalid” names. Instead, caching DNS servers SHOULD generate immediate NXDOMAIN responses for all such queries. This is to avoid unnecessary load on the root name servers and other name servers.

Loopback

Caching DNS servers SHOULD recognize localhost names as special and SHOULD NOT attempt to look up NS records for them, or otherwise query authoritative DNS servers in an attempt to resolve localhost names. Instead, caching DNS servers SHOULD, for all such address queries, generate an immediate positive response giving the IP loopback address, and for all other query types, generate an immediate negative response. This is to avoid unnecessary load on the root name servers and other name servers.

Normal

Caching DNS servers SHOULD NOT recognize example names as special and SHOULD resolve them normally.

Trait Implementations

impl Clone for CacheUsage

fn clone(&self) -> CacheUsage

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl PartialEq for CacheUsage

fn eq(&self, other: &CacheUsage) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for CacheUsage

impl Eq for CacheUsage

impl StructuralPartialEq for CacheUsage