[Freeipa-users] Two kerberos realms for same domainname?

[Simo Sorce]

On Wed, 2013-05-08 at 16:41 +0000, Johnny Westerlund wrote:
> Hi all
> 
> I'm planning implementing a IPA server at a site where there is
> allready a working Active directory domain.
> I would still like the machines from AD and IPA live in the same DNS
> domain.
> 
> 
> Example.
> AD Domainname = foo.bar
> AD KERBEROS realm = FOO.BAR
> a Host principal would look like: host/host1.foo.bar at FOO.BAR
> 
> 
> Now i would like to introduce the IPA server under a different realm
> name but for the same DNS name.
> 
> 
> IPA domainname = foo.bar
> IPA KERBEROS realm = LINUX.FOO.BAR (or what ever)
> a Host principal would look like: host/host2.foo.bar at LINUX.FOO.BAR
> 
> 
> So basicly i would register the hostnames / PTR records in the
> microsoft DNS and use the IPA kerberos REALM for authentication.
> 
> 
> Am i making any sense? is this asking for a world of hurt?

It is possible, and it will hurt.

You will not be able to use trusts between AD and IPA.
You will not be able to use Kerberos between Windows client and Linux
Servers and vice-versa.

I personally discourage people from doing this if they can and instead
delegate (or just forward on both sides) a subdomain (like ipa.foo.bar)
to ipa for all the ipa hosts (server.ipa.foo.bar,
clientX.ipa.foo.bar ...)

Simo.

-- 
Simo Sorce * Red Hat, Inc * New York