Changing DNS Providers without Downtime

This article will guide you through the process of moving DNS services for an existing domain to a new provider without experiencing downtime. For the purposes of this article, we will use Custom DNS as the example service, though you can just as easily apply the information here to Secondary DNS zones or even other DNS providers.

Making The Switch

Create new Custom DNS zone

The first step is to create Custom DNS for your domain. Log into your DynDNS.com account and click Add Zone Services to begin the service creation process. Once the zone has been purchased, you can view and edit the service here.

Duplicate records from your old zone

One of the most important rules when changing DNS providers is to ensure that your old zone and new zone are identical at the start of the process. This will help prevent caching errors and keep your users from receiving conflicting results (see Potential Problems for more information). Simply recreate all of the records from your old DNS provider's settings in your Custom DNS zone, such as A, CNAME and MX records. When you are finished, the old zone and new zone should look the same.

Preactivate Custom DNS

Normally, a Custom DNS zone will only activate once the domain has been delegated to the DynDNS.com nameservers. To help prevent even a few minutes' worth of downtime, it is important that you preactivate your zone. Preactivation forces our servers to load the records prior to delegation; in addition to ensuring our servers are answering before the delegation change is submitted, this also allows you to query our nameservers with dig or NSLOOKUP to double-check your configuration for potential errors.

Preactivation is easy: Visit the configuration page for your zone, click the Preferences button, then click Force Activation at the bottom of the Preferences page.

Wait two hours for preactivation

Preactivation can take a little while to ensure all of our nameservers have fully loaded your zone. To absolutely ensure that our servers have been preactivated, please wait two hours after clicking Force Activation before continuing.

Change nameserver delegation

It's finally time to submit the delegation change to your registrar. In most cases, you can change the delegation for your domain by visiting your domain registration settings in your registrar account, locating the list of nameservers, and setting the values to the new servers. Our list of Custom DNS nameservers can be found here. (If you are using DynDNS.com as your registrar, simply visit the configuration page for your domain registration, click Edit Nameservers, and click Set to Custom DNS Nameservers. We will automatically configure your nameserver delegation for you.)

Depending on the TLD of your domain, the delegation change may take as little as fifteen minutes to complete, or upwards of a day. If the change doesn't appear to take effect right away, don't worry; you are likely seeing a caching issue, which will clear with time (see the next step and Potential Problems). New visitors to your domain should receive the new information immediately.

Wait four days before making changes

While new, non-cached queries will retrieve records from your new Custom DNS zone immediately after the delegation change takes effect, it can take between two and four days for old, cached information to clear. This can result in visitors asking your old DNS provider for information instead of your Custom DNS zone. If you change your delegation, then move your mail server to a new IP address, some senders may still try to deliver mail to the old IP because the old DNS provider is still giving out that information.

To prevent these problems:

  • Don't make any sigificant changes to your DNS. Any good transition takes place over a period of time; if you are moving your DNS, webhosting and mailhosting to greener pastures, it's best to move the DNS first, wait four days for the cache to clear, then move the other services. This ensures all new queries are answered by Custom DNS and prevents confusion.
  • If you do, update both Custom DNS and your old DNS zone. If you really do need to move everything at once, make sure you reflect any changes in your DNS at both your new and old providers. This way, no matter who receives the query (Custom DNS or the old DNS provider), the answers are identical.

After about four days, all new queries will be answered by Custom DNS, and you may safely deactivate your old DNS servers.

Transfer registration

If you are also transferring your domain registration to a new registrar, this step should be completed after you have changed DNS providers. Domain transfers can take up to seven to ten days to complete, during which you cannot modify the nameserver delegation; if you begin the transfer process and your previous DNS provider decides to shut off DNS services (see below), you will be unable to fix the problem for the duration of the transfer attempt. The best advice is to simply wait for the delegation to complete and potential caching issues to completely pass before beginning your transfer; regardless of the state of the registration, your domain will continue to resolve properly during the transfer.

Potential Problems

There are a couple potential issues when moving your DNS services, which usually involve your previous DNS provider. Some DNS providers will immediately terminate their services if you attempt to delegate your domain away from them or transfer the registration to a new registrar; since it may take up to four days for all new queries to come to us, visitors may receive a "does not exist" response from the old provider. (Note: DynDNS.com does not terminate services on delegation change or registration transfer. Custom DNS and Secondary DNS will continue to respond to queries for up to two weeks after a delegation change.)

Unfortunately, if your old provider chooses to turn off your DNS services the moment you submit a delegation change, there isn't much you can do to prevent this. You can try to mitigate the potential downtime by setting high TTLs for your records, which will reduce the chance of visitors needing to query during the downtime. It's also important to talk to your old DNS provider to ensure they will keep their DNS servers answering for your domain for as long as possible after the delegation, or at least verify whether or not they will disable services to help prepare for the move.