このReverse IP Lookupについて
逆引き参照ツールは、逆IPルックアップを実行します。
Takes a domain or IP address and does a reverse lookup to quickly shows all other domains hosted from the same server. Useful for finding phishing sites or identifying other sites on the same shared hosting server.
The Reverse Lookup tool will do a reverse IP lookup. If you type in an IP address, we will attempt to locate a DNS PTR record for that IP address. You can then click on the results to find out more about that IP Address. Please note that in general, your ISP must set up and maintain these Reverse DNS records (i.e. PTR records) for you.
A reverse IP domain check takes a domain name or IP address pointing to a web server and searches for other sites known to be hosted on that same web server. Data is gathered from search engine results, which are not guaranteed to be complete. App provides interesting visual reverse IP lookup tool.
Find all the domains hosted on a given IP address.
Track the domains that come and go on a competitors IP address.
Expand research on a target domain name By using Reverse IP Lookup you can often find other domains owned by a given individual. In cases of Whois privacy on a target domain, knowing other connected domains might surface one with valid owner information.
In computer networks, a reverse DNS lookup or reverse DNS resolution (rDNS) is the querying technique of the Domain Name System (DNS) to determine the domain name associated with an IP address – the reverse of the usual "forward" DNS lookup of an IP address from a domain name.[1] The process of reverse resolving of an IP address uses PTR records. rDNS involves searching domain name registry and registrar tables. This may be used to try to identify the originator’s domain name to track, for example, a spammer sending spam emails or the domain name of a computer trying to break into a firewall or someone trying to hack the system. It may also be used to determine the name of the internet service provider assigned to a particular IP address. The reverse DNS database of the Internet is rooted in the .arpa top-level domain.
Although the informational RFC 1912 (Section 2.1) recommends that "every Internet-reachable host should have a name" and that "for every IP address, there should be a matching PTR record," it is not an Internet Standard requirement, and not all IP addresses have a reverse entry.
IPv4 reverse resolution
Reverse DNS lookups for IPv4 addresses use the special domain in-addr.arpa. In this domain, an IPv4 address is represented as a concatenated sequence of four decimal numbers, separated by dots, to which is appended the second level domain suffix .in-addr.arpa. The four decimal numbers are obtained by splitting the 32-bit IPv4 address into four octets and converting each octet into a decimal number. These decimal numbers are then concatenated in the order: least significant octet first (leftmost), to most significant octet last (rightmost). It is important to note that this is the reverse order to the usual dotted-decimal convention for writing IPv4 addresses in textual form.
For example, to do a reverse lookup of the IP address 8.8.4.4 the PTR record for the domain name 4.4.8.8.in-addr.arpa would be looked up, and found to point to google-public-dns-b.google.com.
If the A record for google-public-dns-b.google.com in turn pointed back to 8.8.4.4 then it would be said to be forward-confirmed.