"RDNS" redirects here. For nursing services in Australia, see Royal District Nursing Service.
Not to be confused with Reverse domain name notation.
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. 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.
^"Reverse DNS". Cloudflare. Archived from the original on 30 March 2019. Retrieved 25 July 2019. A reverse DNS lookup is a DNS query for the domain name associated with a given IP address. This accomplishes the opposite of the more-commonly-used forward DNS lookup, in which the DNS is queried to return an IP address.
and 23 Related for: Reverse DNS lookup information
computer networks, a reverseDNSlookup or reverseDNS resolution (rDNS) is the querying technique of the Domain Name System (DNS) to determine the domain...
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is used to establish the TTL for the negative answer. A reverseDNSlookup is a query of the DNS for domain names when the IP address is known. Multiple...
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Forward DNS (Or Forward DNSLookup)? - Definition from Techopedia". 23 October 2012. "Understanding Forward and ReverseLookup Zones in DNS". 10 February...
IP aliasing IP multicast List of assigned /8 IPv4 address blocks ReverseDNSlookup Virtual IP address WHOIS DOD Standard Internet Protocol. DARPA, Information...
Blackhole DNS servers are Domain Name System (DNS) servers that return a "nonexistent address" answer to reverseDNSlookups for addresses reserved for...
conduct a reverseDNSlookup on the user and then compare the returned host to the hosts in the G-line list. This results in delay, and, if the DNS doesn't...
DNSlookup contains an RRSIG DNS record, in addition to the record type that was requested. The RRSIG record is a digital signature of the answer DNS...
original block was returned to IANA. For reverseDNSlookup, IPv6 addresses were originally registered in the DNS zone ip6.int, because it was expected that...
— the DNS resolver and cache. tinydns — a database-driven DNS server. walldns — a "reverseDNS wall", providing IP address-to-domain name lookup only....
supply a username MaraDNS can add both IP records and the corresponding PTR "reverseDNSlookup" record. It can be used as a master DNS server, and, with...
networks often do not properly configure DNS services for addresses used internally and attempt reverseDNSlookups for these addresses, causing extra traffic...
already results in more than two void lookups and hence PERMERROR. Mechanisms ip4, ip6 and all need no DNSlookup. To enable rapid testing and deployment...
AAAA lookups as required to determine the IP address of the target hostname RFC 821 was published in 1982. It makes only passing references to DNS, because...
address in a DNSBL is thus similar to looking it up in reverse-DNS. The differences are that a DNSBL lookup uses the "A" rather than "PTR" record type, and uses...
In combination with poorly configured DNS (with no reverselookup zone) using RFC 1918 addressing, reverseDNS updates using this authentication scheme...
same year DNS was first created. Early versions did not query DNS and only performed /etc/hosts lookup. The 4.3BSD (1984) version added DNS in a crude...
nslookup (from name server lookup) is a network administration command-line tool for querying the Domain Name System (DNS) to obtain the mapping between...
stored in the Domain Name System (DNS) as ASCII strings using Punycode transcription. The DNS, which performs a lookup service to translate mostly user-friendly...
number of another subscriber, which leads to an ENUM lookup (such as is provided by SIP Broker). The DNS responds to the caller by returning a list with NAPTR...
It used a reverse domain name notation. It was proposed in 1983 and used until the superficially similar Internet Domain Name System (DNS) was fully...
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