ISC's libbind provides the standard resolver library, along with header
files and documentation, for communicating with domain name servers,
retrieving network host entries from /etc/hosts or via DNS, converting
CIDR network addresses, performing Hesiod information lookups,
retrieving network entries from /etc/networks, implementing TSIG
transaction/request security of DNS messages, performing name-to-address
and address-to-name translations, and utilizing /etc/resolv.conf for
resolver configuration.