Types of DNS records

The following records are supported by GeoScaling DNS2: A, CNAME, MX, AAAA, TXT, AFSDB, CERT, DNSKEY, DS, HINFO, KEY, LOC, NAPTR, NSEC, PTR, RP, RRSIG, SPF, SSHFP, SRV, and if this features is activated, NS. You can find a list of RFC documents about these record types here.

The following is a list of important types of records, and a short description:


A

A records are normal subdomains that point to IP addresses. If you want yourdomain.com and www.yourdomain.com to both to point to the IP address 1.2.3.4, you need to define two A records:

yourdomain.com

  • name: leave blank (geoscaling automatically sets this to yourdomain.com after you submit the record)
  • type: A
  • content: 1.2.3.4
  • ttl: 300 (default - this is 300 seconds, that is 5 minutes)
  • priority: 0 (default is 0, leave 0 as the priority is ignored when it comes to A records)

www.yourdomain.com

  • name: www (geoscaling automatically adds yourdomain.com after the www in name when you submit the record)
  • type: A
  • content: 1.2.3.4
  • ttl: 300 (default - this is 300 seconds, that is 5 minutes)
  • priority: 0 (default is 0, leave 0 as the priority is ignored when it comes to A records)

A subdomain can have more than one A record. For example, if you have two mirrors with the same content you can add two A entries for the subdomain, and both entries will be sent to the client, achieving what is called Round robin DNS.


AAAA

Equivalent to the A record, but only accepts IPv6 IP addresses. A subdomain can have both A and AAAA records.


MX

MX is an acronym for Mail eXchanger. This record defines the e-mail servers that receive e-mail for a domain or subdomain. More than one MX record can be defined for a domain.

If you want to add the alt1.aspmx.l.google.com server as an MX with priority 5 for your domain, you need to define it like this:

alt1.aspmx.l.google.com

  • name: leave blank (geoscaling automatically sets this to yourdomain.com after you submit the record)
  • type: MX
  • content: alt1.aspmx.l.google.com
  • ttl: 300 (default - this is 300 seconds, that is 5 minutes)
  • priority: 5

Read more about this record and about MX priority here.


CNAME

CNAME is an acronym for “Canonical name”. CNAME records define aliases. Let's say you have a server called picard, and several subdomains for yourdomain.com, all of them hosted on this. If you define all yourdomain.com subdomains as A records pointing to your picard server, this will work just fine. But if at some point you decide to change the IP address of picard, you will need to manually edit all A records and set them to the new IP address. With CNAME records you don't have to. Just define one A record picard.yourdomain.com with the IP address of the server, and define CNAME records pointing to picard.yourdomain.com for all your subdomains. When a client requests the IP address for subdomain.yourdomain.com, and that subdomain has a CNAME records pointing to picard.yourdomain.com, the client will eventually get the IP address of picard.yourdomain.com. So if at some point you need to change the IP address of the server, you only need to change the A record that defines picard.yourdomain.com.

CNAME records can point to external domains also, not only to subdomains. www.yourdomain.com can point to anothersubdomain.anotherdomain.com, or you asubdomain.yourdomain.com.

 
types_of_dns_records.txt · Last modified: 2015/01/30 00:27 by mstenz
 
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