How to migrate DNS correctly

Question

Client has DNS at a telephone company which provide emails for his domain (sudamerica.cl). I need to switch DNS in order to get control over them so I can properly set the A records for the new website, and the intranet.sudamerica.cl for the Intranet website.

I have suceeded before by coping the MX record by doing nslookup with http://network-tools.com/nslook/, the pop records and so on... but many other times it has failed without explanaition.

Is there any other records beside MX records that must be migrated? What I can do to ensure DNS is correclty configured for email delivery?

Answer 1

MX records and TXT records (SPF), as well as A or CNAME records for related devices (those named in the MX records, or referenced in the SPF config in the TXT record), are all important for mail delivery.

Your best bet for a smooth migration is to obtain a copy of the zone file or a list of all the entries; excepting a zone transfer (which shouldn't be allowed) there isn't really any better way to make sure you get all the records moved over.

Beyond that, for a smooth transition you'll want to make sure that you've got the new DNS server up and running and serving requests before flipping the switch in their domain registration to point to the new name servers.

Answer 2

It sounds like you want to migrate DNS from an outsourced DNS provider, the ISP, to managing DNS yourself.

To start this process, first dial down the TTL for your records on your existing server. This will help you migrate more quickly and efficiently. You need to get a full copy of the existing zone(s) on your new DNS server. Don't change any records just yet.

Once you get your nameserver configured correctly you can contact the registrar and begin the process of setting your NS records. You'll want to set up at least one secondary nameserver, probably as a slave.

Once you have migrated away from the ISP DNS servers you are in good shape. Make changes as necessary and then you can reset the TTL back to your previous default.