Hello Guys.

I really hope someone can help me resolve this asap. I have spent hours upon hours pouring through blogs and forums and applied and double checked every conceivable autodiscover tool and can not resolve this.

Scenario: Server 2012 Standard with Exchange 2013. Split-Brain DNS, (Internal = domain.local) (External = mail.domain.com.na)

I have applied CNAME, PTR, SRV and Autodiscover.xml, but still Exchange Connectivity (Autodiscover) keeps failing on all points.

Everything else is working 100%, OWA, Activesync, IMAP etc.

But I have 1 client PC with Windows 8 Single Language that can obviously not join the domain, and the client doesn't want to use IMAP saying it looks different?? Don't know why. But he wants to use Exchange.

From outlook 2013 I configure it as follows:

Server: server.domain.local

Username: domain user account

Exchange Proxy Server: mail.domain.com

Connection: SSL, HTTP and HTTPS, authentication "auto negotiate"

It just comes back with "Unable to resolve username"

Is it necessary to, as with "mail.domain.com" point "autodiscover.domain.com" to the public IP?

Thank you in advance.

Kind Regards

Hentie Loots

• Edited by EagleClaw1976 Sunday, July 05, 2015 2:26 PM

Hello Ed and thank you for the reply.

This is exactly where I get a bit hazy.

Some of the forums I have read talk about "internal" and "external" DNS Zones.

Internal is fine. But what do you mean by "External / Internet" DNS? Is it something my ISP has to setup on the internet dns? Like with the MX Records that point mail.domain.com to the public IP? Or is it a new zone I need to create on the Server's DNS? Reverse Lookup Zone or something?

I can't find anything on the web about "External DNS Zone". I completely lost with where exactly on this split-brain dns between .local and .com and Foreward and Reverse Lookup Zone I need to create the PTR, SRV, CNAME and A records.

Like I said, everything else works like a well oiled machine. It is only the Autodiscovery from the internet that keeps failing, so Outlook keeps saying exchange is offline and it wasn't able to resolve the username.

I get the same issue even when connected via VPN.

"The action cannot be completed. The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action."

Hoping to hear back soon.

Thanks again.

Hentie Loots

• Edited by EagleClaw1976 Sunday, July 05, 2015 7:14 PM

This is the response I get.

<Autodiscover>

<Response><Error Time="11:46:31.9846029" Id="2220214705">

<ErrorCode>600</ErrorCode>

<Message>Invalid Request

</Message><DebugData/>

</Error>

</Response>

</Autodiscover>

From what I saw with a quick google search, is that this is correct and normal?

• Edited by EagleClaw1976 Monday, July 06, 2015 10:54 AM

Ok Ed.

So this is how I am understanding things now from testing in a Virtual Environment and with your help.

Public Side (ISP) Autodiscover and CNAME record pointing to the public ip address of the onsite router.

Internal side (DNS) Split-Brain DNS

Forward Lookup Zone

              domain.local       Nothing

              domain.com        A Record "mail" pointing to server IP

                                         A Record "autodiscover" pointing to server IP

Is that about right?

Regards

Hentie

If you truly have split-brain DNS, which I think you should have, then lose domain.local and use domain.com for all URLs both internal and external.

What you say is correct.  Internal DNS will have records with the internal IP address, and Internet DN will have records with the external IP address.