My domain registrar is Company A and we use two of their nameservers for DNS. We host our own server hardware in a datacenter that's not affiliated with Company A. Everything about Company A sucks. So we've set up a new account on DNSmadeeasy.com and I copied all our A, MX, and CNAME records over (they take care of SOA and NS). Now, when I log in to my registrar's panel and switch the name servers from theirs to DNSME, are we going to experience any sort of interruption in service?
My initial thought it no, we shouldn't. As with any DNS changes, propagation can take up to 72 hours, but if certain name servers don't have the updated zone files yet, they'll most likely used cached information which is all the same (because NO IP addresses are changing… it's an exact replica).
So what do you think? Should I go ahead and make the change or should I pick a scheduled date and notify clients that they may experience connectivity issues within the 72 hour window?
UPDATE:
Nearly 72 hours have passed and we didn't even have as much as a hiccup. Throughout the last 72 hours I've used nslookup to query several different servers for my NS records and it took about 48 hours for all of them to show the new name servers. The whois information changed almost immediately. So bottom line for anyone that has the same worries as I did, as long as the new DNS providers have the exact same zone information, you won't have any issues.
Best Answer
No, as long as both sets of nameservers have the same records you'll experience no downtime.