On 7 Feb 2018, at 21:51, Andrew Meyer via FreeIPA-users <freeipa-users@lists.fedorahosted.org> wrote:

We are trying to deploy FreeIPA in our environment, this will be a mix of local servers and server to manage auth in EC2.  We have a vpn tunnel setup and are able to communicate across it.  Ina Amazon Linux 2 instance I was able to get FreeIPA installed as a client and am now trying to promote it to a replica.  However I am getting the following error:

[ec2-user@freeipa-host ~]$ sudo ipa-replica-install --setup-ca --ssh-trust-dns --mkhomedir --setup-kra
Password for admin@domain.NET:
ipa         : ERROR    Reverse DNS resolution of address 10.10.52.158 (infra-freeipa1-aws.gatewayblend.net) failed. Clients may not function properly. Please check your DNS setup. (Note that this check queries IPA DNS directly and ignores /etc/hosts.)

Doing some digging on Google I found this
https://yyhh.org/blog/2017/12/freeipa-aws-ec2.  

In this instance DNS was NOT setup on the FreeIPA machine in AWS and fqdn were setup in /etc/hosts and /etc/hostname.  

1) is the the preferred method?
2) Could I still install DNS on the server in AWS to ONLY manage an internal zone?

Hello Andrew!
In this case, the note in your error message is important: There is no reverse address for 10.10.52.158 in FreeIPA. You’ll need to access it and add the reverse zone in Network Services -> DNS and add a PTR entry for your new replica (10.10.52.158).

After this you shouldn’t have problems with setting up replicas. If you use a VPN, you may have to set up a split-horizon DNS, so that your replication traffic will go through the VPN.

--
Aljaž Srebrnič a.k.a g5pw
My public key:  https://g5pw.me/key
Key fingerprint = 2109 8131 60CA 01AF 75EC  01BF E140 E1EE A54E E677