DNS
To be able to show a website and send/receive mail, a computer needs to know where these services are being hosted for every domain name. To this end, the internet uses the DNS (Domain Name System). Within this system, a domain name that a human types into the browser is being translated into the associated IP address (a number that computers use to communicate with each other). This is very much like looking for a name in the phone book and finding the phone number associated with that name.
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DNS settings in the Service Centre
Greenhost automatically configures the DNS settings when you register a new domain name. When the domain name registration is active, you can immediately start using e-mail accounts and start placing and managing a website, without making any changes to the DNS settings. Would you like to view or change DNS settings, then log in to the Service Centre using your administrator credentials. Under the 'Hosting' tab select the intended domain name from the drop-down on top of the page and click 'DNS Records' in the menu on the left.
Changing DNS settings
In the 'Overview' tab you can change the DNS settings in four different ways:
- Toggle DNS off or on: in some specific cases it could be useful to stop all traffic from and to the respective domain name. You can toggle DNS for the respective domain off or on using the switch.
- Add new record: click the blue button '+ New record' to add a new DNS record. See below for a detailed explanation about adding a DNS record.
- Delete record: to delete a DNS record, click the bin icon of the record you want to delete, in the first column.
- Modify record: you can modify existing DNS records by clicking one of the different fields, changing the content and saving. See below under 'adding a new DNS record' for the meaning and significance of different fields.
Adding a new DNS record
When clicking '+ New record', a drop-down appears where you can fill in the four fields of a DNS record: the Record, Type, Destination and TTL.
Record
The record specifies for which subdomain you want to add a record. Filling in just the name of a subdomain signifies the name of a subdomain extended by the primary domain. (For example: 'www' results in 'www.yourdomain.com'.) Filling in the '@' signifies the primary domain name, for example 'yourdomain.com'.
Type
Type includes the type of DNS reference that is made. In the drop-down you can choose from, among others, the following types:
- A is the most important type, it always refers to an IP address (IPv4).
- AAAA is like A, but refers to an IPv6 address.
- CNAME refers to another domain name, never to an IP address. You can use this type to refer subdomains to your primary domain or to an external domain name, at DNS level.
- MX 10 refers to the full domain name of a mail server, not an IP address. The number 10 signifies the first priority reference to a mail server.
- MX 20 is almost the same as MX 10, but signifies the second priority reference to a mail server.
- TXT is used for for instance SPF, DMARC or site verification. It has the form of text between quotation marks.
Destination
The destination field specifies where you want to point towards. The format this should take depends on the type.
TTL
TTL (Time to Live) signifies the number of seconds that this DNS record may be kept in cache memory. The lower the TTL the faster any changes in the record will become active for visitors or users, but after the TTL has expired a page may load a little bit slower. Keeping this field empty results in a default TTL of 3600 seconds (one hour), which is advised in most cases.
SPF-records
SPF allows you to specify which mail servers are allowed to send email on behalf of your domain name. SPF is set by means of a TXT record in the DNS.
By default, we create a TXT record, in which we allow sending from the Greenhost mail servers. It is possible to adjust this, for example, if you also want to send e-mail from the servers of a newsletter provider, or e-mails with invoices from an external accounting program.
Standard record for SPF
Record: @
Type: TXT
Destination: "v=spf1 include:spf.greenhost.nl -all"
TTL: [leave field empty]
Add server to SPF
If you want to add an extra server to this existing SPF DNS record, you can do so by adding one (or more) includes, in this way:
"v=spf1 include:spf.greenhost.nl include:server2.example.com -all"