During domain name registration you will be asked to specify DNS server addresses through NS-records for this domain. These addresses are given by hosting-provider when buying hosting service. If you haven’t done it yet, you can either skip this step and specify addresses later or specify DNS server addresses that domain registrator offers. For example, NS-records for domain test.ua could be as follows: ns1.test.ua., ns2.test.ua. (always put a dot at the end of name server address).
Note that registration of .UA domain and other regional domains is impossible without previously added domain server to DNS.
There should be at least 2 NS-records, first record will point to primary DNS-server, where will be located zone’s master-file; other records will point to secondary server, where will be located copies of DNS records.
It is important that primary and secondary DNS servers are not located on the same physical server, it is even better that servers are situated in different countries (for example, primary server is in USA and secondary — in Ukraine). It is needed for providing reliable work of your site. If primary server is being crashed, your site will be available for users due to reserve records on secondary server.
Let’s take a look at the example, when client orders registration of a domain name test.ua. Wherein he already has needed site, which is hosted in USA, using Google mail servers and sub-domain forum.test.ua is hosted in Netherlands.
During domain registration he is given three NS records for our servers (if others are not chosen): ns1.skydns.net, ns2.skydns.net.
In domain control panel it looks like that:
test.ua. 86400 NS ns1.skydns.net
test.ua. 86400 NS ns2.skydns.net
Every record is pointed at different DNS server. For example, ns1.skydns.net is pointed at USA server, ns2.skydns.net — at GB server. Such server location almost excludes a possibility of your DNS records being hacked, even if malefactor is able to hack one, your site will still function.
Also the big advantage is that DNS records are not located on the same server, where site is hosted. It means that if client will need to move his site to other hosting, he will not need to transfer records to a new DNS server, it is enough to change IP-address in existing DNS records. All records are easily edited via control panel in your user personal account.
Let’s say that USA server where clients site is located has IP-address 220.127.116.11, server with sub-domain forum.test.ua has IP-address 18.104.22.168, mail server is registered at Google (you can get all the needed data from your hosting-provider).
For correct work you need to tune DNS records on every DNS server like that.
- A-record: test.ua A 22.214.171.124 www.test.ua A 126.96.36.199 forum.test.ua A 188.8.131.52
- MX-record: priority is designated with a number, the less value is entered — the more priority is set up. test.ua. MX 1 ASPMX.L.GOOGLE.COM. test.ua. MX 5 ALT1.ASPMX.L.GOOGLE.COM. test.ua. MX 5 ALT2.ASPMX.L.GOOGLE.COM. test.ua. MX 10 ASPMX2.GOOGLEMAIL.COM. test.ua. MX 10 ASPMX3.GOOGLEMAIL.COM. test.ua. MX 10 ASPMX4.GOOGLEMAIL.COM. test.ua. MX 10 ASPMX5.GOOGLEMAIL.COM.
This way of locating resources serves for increasing security. If malefactor is able to hack the server with your site being hosted there, you will not lose control of mail or subdomains, which means you will be able to notify your visitors or clients that your site was hacked and will be soon recovered. To ensure data recovery possibility, reliable hosting-providers do provide a backup (reserve) service.