Reverse DNS Lookup (rDNS) is the turn around of the standard thing “forward DNS Lookup” where the DNS is asked for the IP address of a specific hostname. In Reverse DNS Lookup, the DNS is the way toward looking into an IP deliver to determine a hostname rather than the a different way. This strategy is frequently used to help analyze organizing related issues or to figure out where network information is going.
An exceptional PTR Record is utilized to store rDNS sections. The name of the PTR Record is the IP address with the portions reverse. Reverse DNS Lookup permit the mapping of a hostname name to an IP address. At the point when a query for a rDNS IP address name is played out, a PTR, or Pointer record write will be returned. This PTR record will contain the forward hostname where the IP is utilized as a part of general, or forward DNS mapping.
Reverse DNS is generally utilized by people for such things as following where a site guest originated from, or where an email message started and so on. Numerous email servers on the Internet are designed to reject incoming messages from any IP address which does not have rDNS.
Regularly, a spammer utilizes an invalid IP address, one that doesn’t coordinate the hostname. An Reverse DNS lookup program inputs IP address of incoming messages to a DNS database. In the event that no legitimate name is found to coordinate the IP address, the server obstructs that message.
So on the off chance that you run your own particular email server, rDNS must exist for the IP address that active email is sent from. It doesn’t make a difference what the rDNS record for your IP address focuses to as long as it is there. On the off chance that you have numerous spaces on one email server, just setup switch DNS to point to whichever hostname you think about essential.