What is a nameserver? | Why do we need nameservers? | What if my nameserver goes down? | What are the technical requirements? | To start or stop the service
The Secondary Nameserver Service is available to any customer with a primary connection to JANET. Under this service JANET(UK) will arrange for a secondary nameserver to be run on your behalf at a remote site on JANET. There is currently no charge for this service.
A nameserver is a computer that is used to convert names into numeric addresses and vice versa.
The simple answer is because computers use numbers to communicate, while people use names, and we need to translate between the two.
A lookup table would work for local addresses, but to hold the names and addresses of all the computers on JANET (let alone on the Internet) the table would be impossibly large and impossible to keep up to date. Instead we spread the load and only keep enough information to know either that an address is in our domain or to know where to send it. The Domain Name Service (DNS) acts rather in the same way that the local sorting office recognises and delivers local mail: it sorts mail for the local region by towns, mail for elsewhere in the UK by region or county, and mail for overseas by point of departure. The postal service relies on sorting centres across the country (and indeed across the world) to keep a mail item travelling in the right direction until it reaches its own local sorting office. Likewise the DNS relies on a set of connected computers, called nameservers, to provide the same service for network transmissions.
It is common practice for all organisations to have more than one nameserver. Ideally you should run a primary and secondary nameserver within your organisation and use an off-site nameserver as a backup, but as a minimum, JANET(UK) recommends that you run your primary nameserver within your organisation, and use a secondary off-site. Many organisations connected to JANET have reciprocal arrangements regarding the provision of off-site secondary nameservers, but if that is not suitable then JANET(UK) can arrange for the JANET Network Operations and Service Centre to provide this service for you.
What are the technical requirements?
In order to use the service, the primary nameserver must permit zone transfers to the nominated secondary nameserver(s). In addition, you should ensure that your firewall permits UDP and TCP traffic between the primary nameserver and the JANET secondary nameserver on port 53. This service does not support DNS NOTIFY transactions.
If you want JANET(UK) to arrange a secondary nameserver on your behalf, contact the JANET Service Desk at service@ja.net who will discuss the details with you and start the process.
If at any point you decide you want to cancel the service and run your own secondary nameserver, just contact the JANET Service Desk at service@ja.net again.
