DNS Migration Between IPs
On occasion, you may need to migrate a domain name from one IP to another. There are several reasons why this would need to be done:
- If you refresh your platform with modern hardware and don't want to migrate IPs.
- If you have multiple servers and want to move a domain between them without disrupting the current IP allocations.
- If you move your sites from your old host to your new servers at Hostway.
Whatever your reason, we can help.
Basically, the plan is:
- Contact Hostway support to help you through this process.
- Prepare the global DNS system and wait until the changes cascade outward.
- Perform the cutover in DNS so the domain points to the new IP.
- Cleanup the DNS record.
A domain name starts with the Domain Registrar record, which tells the world which DNS server knows your IP address the best. For servers and domains hosted with us, that would be our array of public DNS nameservers that we manage internally. These nameservers are the Authoritative Nameservers for your domain.
When a public user looks up your domain name, their workstation consults with their ISP's DNS nameserver for the IP. If it doesn't know, it will forward the lookup to the next DNS nameservers in the chain until one of them responds with the current IP address. That response is packaged with a Time-To-Live (TTL) value, which is a count of how many seconds to remember that DNS lookup until it expires and must be fetched from the Authoritative Nameserver again. This TTL value is important to the migration plans.
The standard TTL on our nameservers is 14400 seconds (4 hours). If left as-is, when the IP is changed in the domain record, global DNS systems would still have the old IP cached for as long as their copy of the record's TTL allows. Some users would be directed to your old IP, while some would be directed to the new. That's why it's important to drop the TTL down to something shorter.
1) If your domain name is served by the nameservers here at Hostway, you will need to submit a work request through the Enterprise Portal to let us know that you wish to migrate a domain name between IPs. Please include your domain name, the old IP, and the new IP. The preparation for domain migration will need to start several hours before the intended cutover. We recommend starting the request a few days before the cutover to ensure a slot on our maintenance calendar.
2) Customarily, when we are made aware that you want to migrate a domain name to a new IP, we take note of the current TTL, set the TTL to 300 seconds (5 minutes), and request that you schedule a maintenance window at some point after the old TTL is to expire. This maintenance window is the cutover.
3) During the maintenance, we will update the DNS entry in our nameservers to the new IP. After 5 minutes, the entire world will have your new IP in their caches. If you notice a need to roll back, let us know and we can revert the changes so you can debug the issue and reschedule another cutover.
4) Once you are satisfied with the new IP, please follow up so we can set the TTL back to its previous value (usually 14400 seconds). At this point, the migration is complete.
There is a way to test the new IP in DNS before actually making changes to the public DNS system.
Your workstation OS should have a facility for setting a manual DNS entry locally on your machine. You can enter the new IP address and your domain name into a static entry on your local "hosts" file, and programs on your workstation will consult that file first for the domain lookup before consulting public DNS. After testing your site at the new IP, you can remove the static entry from your hosts file and your workstation will be return to using the public DNS address for remote accesses.
Consult your Operating System's documentation for more details on the local hosts file.
If you have any questions, or would like to begin your Domain Name migration, we are here to help.