dns.resolveTxt(hostname, callback) Uses the DNS protocol to resolve text queries (TXT records) for the hostname. The addresses argument passed to the callback function is is a two-dimentional array of the text records available for hostname (e.g., [ ['v=spf1 ip4:0.0.0.0 ', '~all' ] ]). Each sub-array contains TXT chunks of one record. Depending on the use case, these could be either joined together or treated separately.

dns.resolveSrv(hostname, callback) Uses the DNS protocol to resolve service records (SRV records) for the hostname. The addresses argument passed to the callback function will be an array of objects with the following properties: priority weight port name { priority: 10, weight: 5, port: 21223, name: 'service.example.com' }

dns.resolveSoa(hostname, callback) Uses the DNS protocol to resolve a start of authority record (SOA record) for the hostname. The addresses argument passed to the callback function will be an object with the following properties: nsname hostmaster serial refresh retry expire minttl { nsname: 'ns.example.com', hostmaster: 'root.example.com', serial: 2013101809, refresh: 10000, retry: 2400, expire: 604800, minttl: 3600 }

dns.resolveNs(hostname, callback) Uses the DNS protocol to resolve name server records (NS records) for the hostname. The addresses argument passed to the callback function will contain an array of name server records available for hostname (e.g., ['ns1.example.com', 'ns2.example.com']).

dns.resolveMx(hostname, callback) Uses the DNS protocol to resolve mail exchange records (MX records) for the hostname. The addresses argument passed to the callback function will contain an array of objects containing both a priority and exchange property (e.g. [{priority: 10, exchange: 'mx.example.com'}, ...]).

dns.resolveCname(hostname, callback) Uses the DNS protocol to resolve CNAME records for the hostname. The addresses argument passed to the callback function will contain an array of canonical name records available for the hostname (e.g. ['bar.example.com']).

dns.resolve6(hostname, callback) Uses the DNS protocol to resolve a IPv6 addresses (AAAA records) for the hostname. The addresses argument passed to the callback function will contain an array of IPv6 addresses.

dns.resolve4(hostname, callback) Uses the DNS protocol to resolve a IPv4 addresses (A records) for the hostname. The addresses argument passed to the callback function will contain an array of IPv4 addresses (e.g. ['74.125.79.104', '74.125.79.105', '74.125.79.106']).

dns.resolve(hostname[, rrtype], callback) Uses the DNS protocol to resolve a hostname (e.g. 'nodejs.org') into an array of the record types specified by rrtype. Valid values for rrtype are: 'A' - IPV4 addresses, default 'AAAA' - IPV6 addresses 'MX' - mail exchange records 'TXT' - text records 'SRV' - SRV records 'PTR' - used for reverse IP lookups 'NS' - name server records 'CNAME' - canonical name records 'SOA' - start of authority record The callback function has arguments (err,

dns.lookupService(address, port, callback) Resolves the given address and port into a hostname and service using the operating system's underlying getnameinfo implementation. The callback has arguments (err, hostname, service). The hostname and service arguments are strings (e.g. 'localhost' and 'http' respectively). On error, err is an Error object, where err.code is the error code. const dns = require('dns'); dns.lookupService('127.0.0.1', 22, (err, hostname, service) => { console.log