## Address ### Address (A) used to resolve a host name to an IPv4 address. This is the most common type of record in a [[DNS]] zone. In a lot of infrastructures, there will be an A record for every client on the network, plus servers, printers, and other connected devices. However, in some environments, client workstations will not be listed as A records—only servers, printers, and other shared resources. ### Address (AAAA) performs the same function as an (A) record, but for resolving a host name to an IPv6 address. ## Canonical Name (CN) (or **alias**) record is used to represent an alias for a host (`A` or `AAAA`). For example, the true name of a web server could be masked as the alias `www.` **CNAME** records are also often used to make [[DNS]] administration easier. For example, an alias can be redirected to a completely different host temporarily during system maintenance. ## DomainKeys Identified Mail (DKIM) used to decide whether you should allow received email from a given source, preventing spam and mail spoofing. `DKIM` can use encrypted signatures to prove that a message really originated from the domain it claims. ## Mail Exchanger (MX) used to identify an email server for the domain. In a typical network, multiple servers are installed to provide redundancy, and each one will be represented with an `MX` record. Each server record is given a preference value with the lowest numbered entry preferred. ## Name Server (NS) > identify authoritative [[DNS]] name servers for the zone. > In most enterprise networks, each zone will have several (at least two) [[DNS]] servers holding a replicated copy of the zone. > Therefore, two or more NS records are configured for redundancy. ## Pointer (PTR) used to resolve IP addresses to Host names i.e. 8.8.8.8 --> https://www.google.com ## Start Of Authority (SOA) > identifies the primary [[DNS]] name server that is authoritative for the zone and is therefore responsible for resolving names in the domain (plus any subdomains). ## Sender Policy Framework (SPF) An `SPF` record is used to list the `IP` addresses or names of servers that are permitted to send email from a particular domain and is used to combat the sending of spam. ## Service Record (SRV) ![[2022-01-10-23-48-27.png]] used to identify a record that is providing a network service or protocol. `SRV` records are often used to locate VoIP or media servers. `SRV` records are also an essential part of the infrastructure supporting Microsoft’s Active Directory; they are used by clients to locate domain controllers, for instance. As with `MX`, `SRV` records can be configured with a priority value. ## Text records (TXT) used to store any free-form text that may be needed to support other network services. A single domain name may have many `TXT` records, but most commonly they are used as part of `SPF` and `DKIM`