How to set up secondary DNS

Getting Started

Secondary DNS is the name given to the service that mirrors the authoritative information for a domain name.

Secondary DNS servers are usually listed after the Primary DNS server when registering a domain name.

To maintain availability, Gradwell DNS servers are distributed on three separate networks, two in the UK and one in the US, this helps us to provide a good balance of availability and performance.

Through our Secondary DNS product, Gradwell can also provide secondary DNS service for your domain.

You simply need to enter the domains in the appropriate part of the control panel, and then enable zone transfers to your server from our secondary servers.

Within a few hours, we will pick up the domain name information and begin providing a secondary DNS service.

Every hour, we will query your server to determine if you have incremented the serial number on your zone. If you have, then we will re-transfer the zone. Currently, our servers will ignore any NOTIFY requests.

Basic Configuration

In order for us to provide secondary DNS services for your zones, you will need to allow transfers from the IP address 193.111.200.200.

We will perform the transfers on this server, before sending the received data to our name servers.

Please ensure that you do not firewall either TCP or UDP traffic on port 53, as we use both to successfully receive your DNS information.

If you are using BIND and you restrict zone transfers, make sure you add an "allow-transfer" statement to your bind configuration file as follows:

zone "domain.dom" IN {
type master;
file "domain.dom.db";
allow-transfer { 193.111.200.200; };
};

Gradwell nameservers

Advanced settings and troubleshooting

If we are unable to correctly transfer the data from your server, we will automatically send you an advisory email.

We will retry approximately one hour after the first failed attempt, and keep retrying at hourly intervals. If we have old data stored on our servers then we will keep on serving that until we can successfully transfer the new data.

This service can also be used to provide ‘hidden primary’ DNS servers, a technique discussed at http://www.oreillynet.com/pub/a/network/excerpt/dnsbindcook_ch07/ and http://www.menandmice.com/knowledgehub/dnsqa/7/