====== Networking - DNS - Common Record Types ======

Common examples of DNS records include:

^DNS Record^Function^
|A|A Records are the most basic type of DNS record. A Records are used to point a domain or subdomain to an IP address.|
|CNAME|CNAME records create an alias to an existing A record.|
|MX|Mail Exchanger (MX) records are used to help route email. MX records differ from A Records and CNAMEs in that they also require a "priority" value as a part of their entry.|
|NS|NS record are used to define which servers serve copies of a zone.|
|TXT|A TXT record is used to store text-based information (e.g., to hold SPF data and verify domain ownership).|

----

===== A record =====

This record maps an IP Address to a hostname.

<code bash>
www      IN    A      192.168.1.12
</code>

----

===== CNAME record =====

Used to create an alias to an existing **A record**.

<code bash>
web     IN    CNAME  www
</code>

<WRAP info>
**NOTE:**  You cannot create a CNAME record pointing to another CNAME record.
</WRAP>

----

===== MX record =====

Used to define where email should be sent to.

<code bash>
@       IN    MX  1   mail.example.com.
mail    IN    A       192.168.1.13
</code>

<WRAP info>
**NOTE:**  Must point to an **A record**, not a **CNAME**.
</WRAP>

----

===== NS record =====

Used to define which servers serve copies of a zone.

<code bash>
@       IN    NS     ns.example.com.
@       IN    NS     ns2.example.com.
ns      IN    A      192.168.1.10
ns2     IN    A      192.168.1.11
</code>

<WRAP info>
**NOTE:**  It must point to an **A record**, not a **CNAME**.

This is where Primary and Secondary servers are defined.
</WRAP>

----

===== TXT record =====

Used to store text-based information:

<code bash>
example.com.   IN   TXT   "This domain name is reserved for use in documentation"

# The character string from a TXT record used for SPF:
"v=spf1 ip4:192.0.2.0/24 ip4:198.51.100.123 ip6:2620:0:860::/46 a -all"

# An example of use for DMARC:
"v=DMARC1;p=none;sp=quarantine;pct=100;rua=mailto:dmarcreports@example.com;"

# Use for site verification:
"google-site-verification=6P08Ow5E-8Q0m6vQ7FMAqAYIDprkVV8fUf_7hZ4Qvc8"

# Use for custom email service:
_amazonses.example.com.   IN   TXT   "pmBGN/7MjnfhTKUZ06Enqq1PeGUaOkw8lGhcfwefcHU="

</code>

<WRAP info>
**NOTE:**  Text records can be used:

  * for sources outside of your domain.
  * to hold SPF data and verify domain ownership.

</WRAP>