[Freeipa-users] CentOS 7 & FreeIPA 4.2: DNS resolution at the top-level domain/zone

[Petr Spacek]

On 21.6.2016 15:03, Dan.Finkelstein at high5games.com wrote:
> Solution found (or, if not, a workaround):
> IPA replicas must be named in the root domain/zone and not in a subdomain, else DNS fails to serve records in the root domain. Once we changed our configuration to reflect this, DNS returned to normal.

This is most likely a workaround for some sort of misconfiguration, FreeIPA
itself does not require anything like that.

Petr^2 Spacek


> From: <freeipa-users-bounces at redhat.com> on behalf of Daniel Finkestein <Dan.Finkelstein at high5games.com>
> Date: Tuesday, June 21, 2016 at 07:21
> To: "freeipa-users at redhat.com" <freeipa-users at redhat.com>
> Subject: Re: [Freeipa-users] CentOS 7 & FreeIPA 4.2: DNS resolution at the top-level domain/zone
> 
> Hi Petr,
> 
> Top level means the root zone of the various DNS trees we serve. For example, h5g.com would be the root and dev.h5g.com, test.h5g.com, etc., would be the subdomains. Our subdomains query fine, but any hosts in the root domain no longer resolve.
> 
> An example of an unresolvable name is IPA itself: ipa.h5g.com. Here's output from dig:
> 
> root at ipa ~]# dig ipa.h5g.com
> 
> ; <<>> DiG 9.9.4-RedHat-9.9.4-29.el7_2.3 <<>> ipa.h5g.com
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 52405
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
> 
> ;; OPT PSEUDOSECTION:
> ; EDNS: version: 0, flags:; udp: 4096
> ;; QUESTION SECTION:
> ;ipa.h5g.com.                                      IN            A
> 
> ;; Query time: 0 msec
> ;; SERVER: 10.55.10.31#53(10.55.10.31)
> ;; WHEN: Tue Jun 21 07:15:14 EDT 2016
> ;; MSG SIZE  rcvd: 42
> 
> We expect that its IP address returns from dig, but it doesn't.
> 
> We have 100 zones defined, including forward and reverse zones — all active.
> 
> We do use DNS forwarding, but in a very unsophisticated way: we set up the forwarders to go to Google if our DNS can't resolve a name.
> 
> Thanks and regards,
> Dan
> 
> [cid:image002.jpg at 01D1CB9B.D6819140]<http://www.high5games.com/>
> Daniel Alex Finkelstein| Lead Dev Ops Engineer
> Dan.Finkelstein at h5g.com<mailto:Dan.Finkelstein at h5g.com> | 212.604.3447
> One World Trade Center, New York, NY 10007
> www.high5games.com<http://www.high5games.com/>
> Play High 5 Casino<https://apps.facebook.com/highfivecasino/> and Shake the Sky<https://apps.facebook.com/shakethesky/>
> Follow us on: Facebook<http://www.facebook.com/high5games>, Twitter<https://twitter.com/High5Games>, YouTube<http://www.youtube.com/High5Games>, Linkedin<http://www.linkedin.com/company/1072533?trk=tyah>
> 
> This message and any attachments may contain confidential or privileged information and are only for the use of the intended recipient of this message. If you are not the intended recipient, please notify the sender by return email, and delete or destroy this and all copies of this message and all attachments. Any unauthorized disclosure, use, distribution, or reproduction of this message or any attachments is prohibited and may be unlawful.
> 
> From: <freeipa-users-bounces at redhat.com> on behalf of Petr Spacek <pspacek at redhat.com>
> Organization: Red Hat
> Date: Tuesday, June 21, 2016 at 06:04
> To: "freeipa-users at redhat.com" <freeipa-users at redhat.com>
> Subject: Re: [Freeipa-users] CentOS 7 & FreeIPA 4.2: DNS resolution at the top-level domain/zone
> 
> On 21.6.2016 11:23, Dan.Finkelstein at high5games.com<mailto:Dan.Finkelstein at high5games.com> wrote:
> We've recently set up a "clean" install of FreeIPA replete with replicas, but we just noticed an odd behavior in the DNS service: hosts in the top level domain (like ipa.example.com) do not resolve, whereas hosts in subdomains (like ipa.dev.example.com) do. I'm not sure what to look for in the various log files but I don't see any obvious errors. I thought perhaps this might have some guidance https://www.redhat.com/archives/freeipa-users/2015-July/msg00102.html, and maybe it does, but I'm not sure how to rescue my top-level domain names.
> 
> Hi,
> 
> we can certainly debug this but first of all, please clarify what 'top-level'
> means.
> 
> If you really want help please do not obfuscate any DNS names. It often hides
> real problems while not improving security in any way. (BTW you do not need to
> hide domain names like 'NY5-EXMB1.High5.local' because these already leaked
> through e-mail headers :-)
> 
> So, here are the important questions:
> 0) What name is unresolvable?
> $ dig the.problematic.name.example.
> 
> 1) What is the expected result from "dig"?
> 
> 2) What DNS zones are configured in IPA?
> $ ipa dnszone-find
> 
> 3) Do you use DNS forwarding? (--forwarders option during IPA install or
> commands ipa dnsforwardzone-*, ipa dnsconfig-mod etc.)