Why use reverse DNS lookup?

How to do DNS lookup in CMD?

As an example I have a domain(example.com). I registered it on godaddy.

Now if a guy is trying to connect to that domain he has to type below in CMD. Nslookup -type=mx example.com Here the "." and "-" are optional. What means these two dots and dash

From the man page. type Specifies one of A, AXFR, and TXT. The default is A queries are made to the primary server name. AXFR sends UPDATE requests for a zone without any. change to the primary server. (This is not recommended for DNS environments.) TXT queries are sent to the default (primary) server. for the domain. By default, nslookup uses A queries.linuxmanpages.com
Server: 172.31.10
Address: 172.10#53 Non-authoritative answer: Name: www.com Address: 216.134.193.100
The following query was sent to 172.10: ;; ANSWER SECTION: www.com) 21567 IN A 216.100
(I used IP address for anonymity, but you need the right IP address).

Why use reverse DNS lookup?

Reverse DNS is used for IP address lookup.

We can not just use IP addresses as a substitute for real names, and people are free to pick whatever name they want to have assigned to them, but most of them use domain names and the host name is not the only identifier, especially on local networks. For example, when you access your home network through SSH, you usually enter hostname.local or hostname.domain instead of the actual IP address, and so you can also look it up using hostname, but not just ip.

Another example would be the domain.com/hostname and hostname.domain domains, in which there may be much more than one entry for the same hostname. In fact, you can be looking up your Linux hostname if it is registered on NameCheap.com or whoisip.org. I'm pretty sure there's no need to ask to search for the IP address of your hostname domain, since I already went to a whois website to check what kind of information can be retrieved about that hostname.

As you can see, the hostname isn't the only identifier, and using domain names instead of IP addresses makes a lot of sense, so you can access an identified resource like a web server if it is available using a domain name, and not just an IP address. That's why reverse DNS lookup exists.

Reverse DNS (RID) lookup (sometimes referred to as forward DNS, but reverse DNS is really backward DNS) can be done for many types of data: Hostnames. MAC addresses. IPv6 addresses. Network interfaces. Domain names. Usernames. You don't need a reverse DNS server to reverse the lookup of an IP address, since you already have it when using the network's ARP table. However, the process is somewhat different for hostnames and MAC addresses, domain names and usernames, and network interfaces. So, let's cover the various ways to use the reverse DNS lookup for these pieces of information.

IP address RID lookup. The process for this type of reverse lookup is simple, since it's all about parsing the reverse DNS zone file format to find out which hostname corresponds to which IP address.