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I've been reading around this topic towards understanding whether there's some or no chance of downtime during an upcoming domain transfer for 15 live and very critical domains.

In our case there are three companies involved: CompanyA is the original registrar and DNS host, CompanyB is the new DNS host, and CompanyC is the new registrar.

I've already changed the nameservers for all domains to those of CompanyB. We suffered some downtime because CompanyA deleted their hosted DNS for our domains directly after the change, but the changes propagated and we're now able to configure our DNS with CompanyB.

From what I understand (please correct where wrong!):

  1. There exists an SOA record that points oneofourdomains.com to ns.companyb.com. That record is maintained and authoritatively hosted by the ccTLD registry for the domain (eg. Verisign for .com). CompanyA currently has the ability to change the SOA record because they're the registrar.

  2. There exist NS records for oneofourdomains.com, which are also related to the link from domain name to nameserver, are similarly hosted by the ccTLD, and which CompanyA are also able to change while acting as registrar.

  3. Neither CompanyB nor CompanyC currently have any control over the SOA or NS records.

  4. CompanyA are unable to cause us (DNS) problems during the transfer by dropping service early, because they are not the authoritative source for the SOA and NS records.

  5. When we transfer the domains, it's administrative control of the SOA and NS records that will be transferred to CompanyC.

  6. As long as we advise CompanyC that the SOA and NS records must not change (as regards pointing to CompanyB's nameservers), there's no need for any kind of DNS change, and therefore no possibility of downtime.

Is my understanding of this correct? My fear is that CompanyA will somehow cut us off again, and their support dept hasn't given me much confidence in their understanding of the topic.

jlmt
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2 Answers2

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If the nameservers aren't changed during the transfer, and there's no reason to think they would, then it will go fine without any noticeable interruption in service. I've transferred numerous domains using exactly this procedure.

Michael Hampton
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  • Agreed. If company A can't really cut you off once you transfer the domain away from them if they're no longer hosting any services you rely on. The DNS is already moved which is great. If Company A is hosting the services to which DNS points to (web, mail, etc.) then they could of course mess with those services, but it doesn't sound like that's the case from the description. – briantist Aug 24 '14 at 20:29
  • Valid in general, but not always. Case in point: DNS service is currently provided by the registrar. Some registrars, upon seeing the domain has been transfered out of their sponsorship, will immediately stop DNS resolution for this domain, considering that the contract was ended by the transfer. Because of caches, this abrupt termination may render the domain unresolvable for few hours/days even if the nameservers are changed immediately after transfer, at the new registrar. – Patrick Mevzek Mar 29 '21 at 15:29
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In most TLDs, a transfer has no impact on nameservers, that is a transfer among registrars is an administrative change, not a technical one.

There are exceptions, but few of them.

Except of course if you use the current registrar ALSO as the DNS Provider, which is possible but certainly not required.

To avoid downtime, if you need to change both the registrar and the DNS provider, in the case the DNS Provider is NOT the registrar you can do the following:

  • prepare the zone at new DNS provider to be exactly the same as the one of current DNS provider
  • go to your registrar, change the DNS provider to point to the new one
  • make sure that the old DNS provider continue to respond to DNS queries on your domain for "some" time
  • then after some time go to your new registrar and schedule a transfer to it
  • after "some" time (typically 5 days in gTLDs), the domain will be transfered over to new registrar.

You can of course swap both cases, and do the registrar transfer first and then the DNS provider change.

Note that if the registrar is the DNS provider then it will be more difficult: as soon as you transfer the domain out of it, you risk it stops responding to DNS queries for it. It may not or should not, but it all depends on the contract signed with it. As soon as the transfer is done you are not really anymore in a contract with it and hence it can view things as not needing to provide DNS service anymore. Some registries, like .FR, require (but in practice this is impossible to verify and even more enforce) the old registrar to keep being a DNS Provider for some days. I would avoid this case as much as possible. In such situations it is better to first change the DNS provider so that the current registrar is not the DNS provider anymore, and then change registrars.

Patrick Mevzek
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