

### Commonly used DNS Records

| Type | Description |
| --- | --- |
| **A** | The record that holds the IP address of a domain. |
| **AAAA** | The record that contains the IPv6 address for a domain (as opposed to A records, which list the IPv4 address). |
| **CNAME** | Forwards one domain or subdomain to another domain, does NOT provide an IP address. |
| **MX** | Directs mail to an email server. |
| **TXT** | Lets an admin store text notes in the record. These records are often used for email security. |
| **NS** | Stores the name server for a DNS entry. |
| **SOA** | Stores admin information about a domain. |
| **SRV** | Specifies a port for specific services. |
| **PTR** | Provides a domain name in reverse-lookups. |

### Less commonly used DNS Records

| Type | Description |
| --- | --- |
| **APL** | The ‘address prefix list’ is an experiment record that specifies lists of address ranges. |
| **AFSDB** | This record is used for clients of the Andrew File System (AFS) developed by Carnegie Melon. The AFSDB record functions to find other AFS cells. |
| **CAA** | This is the ‘certification authority authorization’ record, it allows domain owners state which certificate authorities can issue certificates for that domain. If no CAA record exists, then anyone can issue a certificate for the domain. These records are also inherited by subdomains. |
| **DNSKEY** | The ‘DNS Key Record’ contains a public key used to verify Domain Name System Security Extension (DNSSEC) signatures |
| **CDNSKEY** | This is a child copy of the DNSKEY record, meant to be transferred to a parent. |
| **CERT** | The ‘certificate record’ stores public key certificates. |
| **DCHID** | The ‘DHCP Identifier’ stores info for the Dynamic Host Configuration Protocol (DHCP), a standardized network protocol used on IP networks. |
| **DNAME** | The ‘delegation name’ record creates a domain alias, just like CNAME, but this alias will redirect all subdomains as well. For instance if the owner of ‘example.com’ bought the domain ‘website.net’ and gave it a DNAME record that points to ‘example.com’, then that pointer would also extend to ‘blog.website.net’ and any other subdomains. |
| **HIP** | This record uses ‘Host identity protocol’, a way to separate the roles of an IP address; this record is used most often in mobile computing. |
| **IPSECKEY** | The ‘IPSEC key’ record works with the Internet Protocol Security (IPSEC), an end-to-end security protocol framework and part of the Internet Protocol Suite (TCP/IP). |
| **LOC** | The ‘location’ record contains geographical information for a domain in the form of longitude and latitude coordinates. |
| **NAPTR** | The ‘name authority pointer’ record can be combined with an SRV record to dynamically create URI’s to point to based on a regular expression. |
| **NSEC** | The ‘next secure record’ is part of DNSSEC, and it’s used to prove that a requested DNS resource record does not exist. |
| **RRSIG** | The ‘resource record signature’ is a record to store digital signatures used to authenticate records in accordance with DNSSEC. |
| **RP** | This is the ‘responsible person’ record and it stores the email address of the person responsible for the domain. |
| **SSHFP** | This record stores the ‘SSH public key fingerprints’; SSH stands for Secure Shell and it’s a cryptographic networking protocol for secure communication over an unsecure network. |