The Time To Live (TTL) setting in your website's zone file states how long nameservers (which have the job of hunting down the location of the website you wish to navigate to) cache your zone file for. Zone files do not always change that frequently, and so to reduce traffic across the internet and speed things up nameservers will "cache" a zone file after retrieving it. When another requests comes in for that website they will simply use the saved version of the zone file.
However, in order to update its records in case of any changes to the zone file, it will seek out a new version of the zone file once the Time To Live value has been reached. TTL is measured in seconds, for example a value of 86400 means that the zone file will need to be updated 24 hours after the nameserver originally cached it. Lower TTL values are useful if values in your zone file are changing frequently.
Our web hosting services provides you with the flexibility to change the TTL value for individual records in your zone file.
After logging in select Manage Website from the websites box (if you have more than one website hosted with Gradwell you will have to choose the correct one using the dropdown box).
On the next page, click DNS.
You will see a summary of your DNS settings. Select DNS Records to see your zone file records, including the current TTL values.
To add an entry, click on Add New DNS Record.
Select the DNS record type using the dropdown box, and the fields available in the DNS Record Properties area will automatically change to inform you what type of values are required (for example an IP address or hostname). Finally, select whether you wish to use the default Time To Live (TTL) setting or a custom value (see this article for more assistance on TTL).
Your record will automatically be checked to ensure that it is in the correct format. If you have entered any incorrect values you will be notified. For example, in the screenshot below we are trying to enter a hostname as the value in an A record, when in fact A records require an IP address.
The following type of resource records can be used:
- A record: used to map a hostname to an IP address
- AAAA record: used to map a hostname to an IPv6 address
- CNAME record: used to map a hostname to another hostname
- NS record: used to delegate a subdomain to another nameserver
- MX record: used to specify a mail server that accepts emails to that domain
- SRV record: used to define the location of servers for specific services
- TXT record: used to enter human readable text into the zone file