Make #DNS queries using client side #Javascript using DNS-JS
DNS is a very simple protocol, which runs over UDP port 53. It’s primary role is to determine the IP address that is related to a domain. So for example, DNS-JS.com resolves to 95.154.244.106, but it’s also used to determine what server handles the email for a given domain, and lots of other ‘glue’ that holds the internet together.
The issue is, you can’t make a low level packet requests using Javascript alone, so this library helps you make DNS requests using Browser-side javascript.
So, a simple example would be;
DNS.Query(“dns-js.com”,
DNS.QueryType.A,
function(data) {
console.log(data);
});
Which makes a DNS “A” type request for “dns-js.com”, and will return the result as a parameter to your callback function, in this case as “data”, and written to the console.
The full list of Query types are as follows;
A : Address Mapping record NS : Name Server record MD : A mail destination (OBSOLETE - use MX) MF : A mail forwarder (OBSOLETE - use MX) CNAME : Canonical Name record SOA : Marks the start of a zone of authority MB : A mailbox domain name (EXPERIMENTAL) MG : A mail group member (EXPERIMENTAL) MR : A mailbox rename domain name (EXPERIMENTAL) NULL : A Null resource record (EXPERIMENTAL) WKS : A well known service description PTR : Reverse-lookup Pointer record HINFO : Host information MINFO : Mailbox or mail list information MX : Mail exchanger record TXT : Text Record RP : Responsible Person AFSDB : AFS Data Base location AAAA : IP Version 6 Address record SRV : Service Location SSHFP : A SSH Fingerprint resource record RRSIG : RRSIG rfc3755 AXFR : DNS zone transfer request. ANY : Generic any query URI : A Uniform Resource Identifier (URI) resource record CAA : A certification authority authorization
and, you can see other demos at https://www.dns-js.com/
