==== DNS record types ====

=== DNS record types ===

This is a list of some DNS record types which MaraDNS supports.  

A A, or address, records describe the IP that a given DNS node has. 

MaraDNS optionally uses the 'A' to signify an A record. This has one 
data-dependent field: The ip for the node in question, in dotted 
decimal (e.g. 192.168.42.55) format. 

MX MX, or mail exchange, records describe the machines to contact 
in order to send mail to a given DNS node. 

This has two data-dependent fields: The preference for the mail 
exchanger (lower preferences get higher priority), and the name of the 
DNS node to deliver mail to. 

NS A NS record tells name servers which machines are in charge of a 
given domain zone. 

This has one data-dependent field: The name of the DNS node which a 
given NS record points to. 

Any given zone must have one or more NS records. If no NS records are 
present in a zone, MaraDNS will synthesize NS records for the zone in 
question. If one wishes to set up their own NS records, all of the NS 
records for a given DNS zone need to be placed immediately after the 
SOA record. 

MaraDNS also supports delegation NS records, which name the DNS servers 
for a sub-zone, which usually is on another DNS server. DNS allows for 
people to delegate sub-zones in DNS. Just as the "." server delegates 
any name that ends in ".com." to another set of name servers, and the 
".com." name servers, in turn, delegate any names that ends in 
"example.com.", such as "www.example.com.", to the "example.com." name 
servers, the "example.com." name servers may further delegate 
sub-zones. 

For example, if example.com wishes to sub-delegate "john.example.com." 
to John who works at Example, inc., lines like this can be added to the 
example.com zone file:

john.example.com. NS ns1.john.example.com. 
john.example.com. NS ns2.john.example.com. 
# It's important to provide "glue"; in other words, let the world know 
# the IPs for these name servers. 
ns1.john.example.com. 10.9.8.7 
ns2.john.example.com. 10.5.77.65

John, who is running is own nameservers with the IPs 10.9.8.7 and 
10.5.77.65 then has a zone file for john.example.com. that looks 
something like this:

# It is best if the NS records for a subzone agree with the delegation 
# records above 
john.example.com. NS ns1.john.example.com. 
john.example.com. NS ns2.john.example.com. 
 
ns1.john.example.com. 10.9.8.7 
ns2.john.example.com. 10.5.77.65 
 
# Now that that is out of the way, here is the rest of the zone 
john.example.com. 10.9.8.7 
www.john.example.com. 10.5.77.65 
john.example.com. MX 10 mail.john.example.com. 
mail.john.example.com. 10.9.8.7

SOA  This is a record used when using DNS to synchronize data 
between multiple computers. Details on how this record works is in the 
DNS masterdocument. 

A given zone must have precisely one SOA record. If a SOA record is not 
present in a zone file, MaraDNS will synthesize a SOA record. If the 
record is in a zone file, it must be the first line of the zone file. 
Any other use of a SOA record will result in MaraDNS returning an 
error. 

TXT TXT, or text, records are arbitrary text strings which can be 
attached to given DNS nodes. Certain protocols, such as SPF, use this 
field to store protocol-specific data. 

This has one data-dependent field: The text string in question.  
Note that this document does not describe every single record type that 
MaraDNS support. Please refer to the CSV2 manual pagefor a more 
complete reference.  

