Difference Between Reverse Lookup Zone and Forward Lookup Zone
Domain Name System (DNS) is the system of nomenclature that is used by any resource connected to the Internet. DNS translates domain names, which are more expressive to humans in the IP addresses associated with Internet resources to find them all over the world. Each time an IP address is used, the DNS translates the name into the related IP address. Forward lookup zone is the alternative host name for IP address relations. When an IP address is requested by a computer for the name of a specific host, a query is sent to the forward lookup zone to obtain a result. The reverse lookup zone has the IP address to host name mapping. The reverse lookup zone is queried when a computer requests a host name to a specific IP address to receive the response.
What is forward lookup zone?
Forward lookup zone contains a mapping between host names and IP addresses. When a computer requests an IP address by providing a host name (which is easier to use), forward lookup zone is queried to locate the IP address of the given host name. For example, when you type www.cnn.com on your browser, forward lookup zone will be in query and IP address 220.127.116.11 will be given as the result, which is the IP address of the site. When forward lookup is sent to the DNS server, DNS server searches A type resource record linked with the host name provided by the application. A resource type is a DNS record that can be used to show the domain and host names to a static IP address. If the DNS server is able to find identical A type resource record, it will provide that to the client, else it will send the request to another DNS server.
What is the Reverse lookup zone?
Reverse lookup zone has a mapping that links IP addresses to host names. When a computer asks for a domain name by providing an IP address, the reverse lookup zone is challenged to find the host name to IP address given. For example, if a customer wants to see the host name corresponding to IP address 18.104.22.168, the reverse lookup zone will be in query and will come up with the name www.cnn.com. The reverse lookup zone holds PTR resource records. A PTR record allows you to do a reverse lookup by indicating the IP address of a host name / domain. By doing the opposite lookups, these PTR records are used to show records of A resource records.
What is the difference between Forward Lookup and Reverse Lookup Zone?
The main difference between forward lookup zone and the reverse lookup zone is that forward lookup zone is used to resolve forward lookup requests when the client requests an IP address by providing the host name whereas the reverse lookup zone is used to resolve requests related to reverse lookup when a client requests a host name by providing an IP address. Forward lookup zone holds records A type resource records that can show an IP address for a provided hostname. The reverse lookup zone contains PTR records that can show a host name for a given IP address.