Friday, 25 March 2016

DNS Records

DNS Records

Record Type Description Function
A Address record Returns a 32-bit IPv4 address, most commonly used to map hostnames to an IP address of the host.
AAAA IPv6 address record Returns a 128-bit IPv6 address, most commonly used to map hostnames to an IP address of the host.
CNAME Canonical name record Alias of one name to another: Canonical records (CNAMEs) are useful for pointing one host name at another.
MX Mail exchange record Maps a domain name to a list of mail transfer agents for that domain.
MX records are those that are looked up by mail servers when email needs to be delivered. 
NS Name server record A NS record tells recursive name servers which name servers are authoritative for a zone.  Recursive name servers look at the NS records to work out who to ask next when resolving a name.
PTR Pointer record While the A record points a domain name to an IP address, the PTR record resolves the IP address to a domain/hostname. PTR records are used for the reverse DNS (Domain Name System) lookup.
SOA Start of authority record Specifies authoritative information about a DNS zone, including the primary name server, the email of the domain administrator, the domain serial number, and several timers relating to refreshing the zone.
SRV Service record SRV record is a specification of data in the Domain Name System defining the location, i.e. the hostname and port number, of servers for specified services. The SRV records relate to a particular service of the domain, like FTP or SIP, rather than a specific machine the way A or C-name records do.