One of the many challenges that can face a person while attempting to make modifications to a zone file is knowing what all of the different records are used for. This article highlight several of the commonly used records in an attempt to help demystify them.
First lets start with a look at a typical zone file:
;Panel 11.24.4-CURRENT_33868 ; Zone file for liquidweb.com $TTL 14400 @ 86400 IN SOA ns.liquidweb.com. admin.liquidweb.com. ( 2009022402 ; serial, todays date+todays 86400 ; refresh, seconds 7200 ; retry, seconds 3600000 ; expire, seconds 86400 ) ; minimum, seconds liquidweb.com. 86400 IN NS ns.liquidweb.com. liquidweb.com. 86400 IN NS ns1.liquidweb.com. liquidweb.com. IN A 126.96.36.199 localhost IN A 127.0.0.1 liquidweb.com. IN MX 0 liquidweb.com. mail IN CNAME liquidweb.com. www IN CNAME liquidweb.com. ftp IN A 188.8.131.52 cpanel IN A 184.108.40.206 webmail IN A 220.127.116.11 liquidweb.com. IN TXT "v=spf1 a:email.liquidweb.com a:mxgate-02.liquidweb.com a:agile.liquidweb.com a:swift.liquidweb.com mx:liquidweb.com ~all"
Time to Live — The time to live value sets how long this information will be good for when a recursive DNS server queries for information on your domain name. The value is typically set in seconds.
Sate of Authority — The state of authority record specifies the DNS server providing authoritative information about an Internet domain, the email of the domain administrator, the domain serial number, and several timers relating to refreshing the zone.
Nameserver — The servers listed in the NS record are the authoritative nameservers for the domain.
Mail Exchange record — The MX record state the location that mail directed at the domain will be sent. MX records should always be fully qualified domain names, never just an IP address.
Address record — The address record assigns an IP address to a domain or subdomain name. An A record will always be an IP address.
Canonical name — The CNAME record makes one domain name an alias of another. The aliased domain gets all the subdomains and DNS records of the original. To put this in simple terms, a CNAME redirects requests to another record. A CNAME record will always be a fully qualified domain name.
Text Record — A TXT record allows an administrator to insert arbitrary text into a DNS record. The most common implementation of TXT records are for adding SPF records to a domain.
Liquid Web’s Heroic Support is always available to assist customers with this or any other issue. If you need our assistance please contact us:
Toll Free 1.800.580.4985