DNS organizes hostnames in a domain hierarchy. A domain is a collection of sites that are related in some sense because they form a proper network (e.g., all machines on a campus, or all hosts on BITNET), because they all belong to a certain organization (e.g., the U.S. government), or because they’re simply geographically close.
For instance, universities are commonly grouped in the .edu domain, with each university or college using a separate subdomain, below which their hosts are subsumed.
Also Read: Top 10 Online Free Scanners
XYZ University have the xyz.edu domain, while the Science department is assigned as science.xyz.edu.
We have seen that DNS not only deals with IP addresses of hosts, but also exchanges information on name servers. DNS databases may have, in fact, many different types of entries.
A single piece of information from the DNS database is called a resource record (RR). Each record has a type associated with it describing the sort of data it represents, and a class specifying the type of network it applies to. The latter accommodates the needs of different addressing schemes, like IP addresses (the IN class), Hesiod addresses (used by MIT’s Kerberos system), and a few more. The prototypical resource record type is the A record, which associates a fully qualified domain name with an IP address.
Here we’ve listed out top 5 DNS Lookup resources through which you can easily scan DNS against any target IP/Domain.
Most do the same stuff like (ping, traceroute, DNS lookups, etc), but some stand out as providing particularly useful and interesting functionality.