What is Reverse DNS?
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Reverse DNS (Domain Name System) lookup, also known by the acronym (rDNS), candlelight service candles is the procedure by which someone can appear up a host name given a distinct IP address. Reverse DNS is also known in some places as reverse resolving. It is the opposite of DNS lookup, by which a person looks up an IP address given a particular host name.
Why use Reverse DNS?
A reverse DNS lookup is generally performed for troubleshooting purposes. Frequently, tools like a traceroute or a ping will do a reverse DNS lookup monstrance to determine the flow of targeted traffic from 1 point to yet another. An additional typical location for reverse DNS lookup is when accessing a persons email. Numerous contemporary email providers will do reverse DNS lookups to establish if an e-mail was sent from a recognized spam address. Finally, reverse DNS can be employed to make confident that there is a suitable relationship between the owner of a server and analyze finger rosary the owner of a domain name. This strategy, identified as Forward Confirmed reverse DNS (FCrDNS) is utilized to put a quit to phishing sites and spammers.
What is IPv4 Reverse DNS lookup?
IPv4 Reverse DNS is a kind of reverse DNS that utilizes a reverse IN-ADDR entry with the particular domain in-addr.arpa. The IP address represented in the in-addr.arpa domain is written in reverse order to the usual way that the IP address is written. For instance, if a individual was performing a reverse domain lookup for an address such as 192.168.1.1, he would do the lookup utilizing 1.1.168.192.in-addr.arpa.
What is IPv6 Reverse DNS lookup?
IPv6 Reverse DNS lookup is a variety of reverse DNS that uses the unique domain ip6.arpa. As opposed to IPv4 Reverse DNS lookup, IPv6 Reverse DNS lookup does not use the regular IP address style of looking up host names. Rather, it utilizes a sequence of nibbles, or 4 bit aggregations, in reverse order with every single number separated by a period. For example, if a individual was performing a reverse domain lookup for an address such as 2001:0db8:::::1428:57ab he would do the lookup making use of b.a.7.5.8.two.4.1.....8.b.d..1...two.ip6.arpa.
What happens when there are many host names assigned to one IP address?
A reverse DNS lookup will be able to decide all of the host names connected with a specific IP address, though this practice is at times frowned upon. Several cheap net hosting plans will offer shared virtual hosts where several sites share space on the same IP address. Even though this does not affect the validity of the info returned by a reverse DNS lookup, it can lead to difficulties with other services.
