Change DNS Providers with No Downtime
In the past, we’ve shown how to safely change DNS records with no downtime. But we don’t have any articles on changing DNS providers. We did some research and found that there wasn’t anything recent that really dug into DNS provider migrations. Most of the ones we found were dated back to 2011 and further. The Internet and DNS providers’ abilities have changed considerably in that time. And so have our methods to work with them.
Before you start, consider when would be an optimal time to migrate. Keep in mind that for about two days you will not be able to make any changes to your DNS records.
#1 TTL’s
Take note of your TTL’s, short for time to live. TTL’s are a setting in every record that dictate how long a record can be cached. That means, during this period, any resolving nameservers will not query the domain’s nameservers. Instead, it will rely on the information it has cached for that record until it expires.
This is the most crucial part of a migration. You will need to wait out your existing TTL’s before you migrate in order for your new records to fully propagate.
Keep in mind that some records, like NS records, will have a TTL of a few days or even a week. NS records, or nameserver records, are responsible for mapping your domains to your DNS providers’ nameservers. If you fail to wait out the TTL’s for your NS records, you could experience downtime until those TTL’s expire.
Option two, you can lower the TTL’s on your old records, wait it out and then start the migration process when all TTL’s have expired. This way you can shut off your old services within 24–48 hours of migration (depending on the length of your new TTL’s).
#2 Add Domains
While you are waiting for your TTL’s to expire, you can start adding your domains to the new provider. You can add them manually or copy and paste lists of domains using the Bulk Add tool.
#3 Add/Import Records
There a three ways you can add your records to your new provider. You can use an AXFR transfer or a zone import file. An AXFR transfer will pull all of your configurations directly from your old nameservers.
Option two, you can import your records using zone files. Keep in mind, your old provider will need to support exporting zone files.
No matter the method your choose, both providers will need to have identical record configurations for this to work. So if you are considering changing your web host or where your records point to, you will want to wait at least two days after the migration to make those changes.
#4 Go Live
Push your new record configurations live. Depending on your provider, this can take anywhere from a few milliseconds to two days. If you’ve read our other introduction to DNS articles, you’d know the DNS networks use Anycast, or one to many propagation. That means, whenever your update your record configurations, those updates are sent to all nameservers in your provider’s network instantly. Anycast reduces network latency and can also be used to deliver location-specific responses.
DNS Made Easy offers instant DNS record propagation for all of our clients. Of course, you don’t have to choose our services, but you can’t blame us for trying ;)
#5 Test, Test, Test!
Test your new nameservers to make sure your records have propagated. Free monitoring tools, like Sonar Lite’s DNS Lookup, make it easy to check records directly against any nameservers.
#6 Update Your Domain Registrar
This is the service you used to purchase your domain name. You will need to tell them where your new nameservers are. Nameserver changes can take anywhere from 24–48 hours to propagate. During that time, you will need to keep your old provider’s configurations live for about a week before discontinuing services.
Check if your nameservers have been properly switched using the Delegated Nameservers tool in Sonar Lite.
Originally published at DNS Made Easy Blog.
