MSExchangeGuru.com

Well this is not something new but recently I was configuring this for one of my customer so I would like to share the steps here.

So this customer of mine has a private cloud so they have multiple smtp domains. This has been normal until we started using autodiscover url as SCP.

Now every domain’s outlook search for autodiscover.domain.org which can be pointed to the CAS servers. But this needs to have outlook user will get a popup saying autodiscover.domain.org is not present in certificate. And no one like this popup so We configured the following to suppress this.

To explain if we are using 2 smtp domains as mentioned below

Hosted Services provider:    MSExchangeGuru.com

Hosted customer domain:     GO5LLC.com

So customer’s outlook is trying to reach “Autodiscover.GO5LLC.com” and giving the certificate pop up.

1. Create the following folders in all the CAS servers
   

   C:\inetpub\Autodiscoverredirect
   

   
   

   C:\inetpub\Autodiscoverredirect\Autodiscover
   

   
   

2. Add a 2nd NIC card with the same network
   
3. Create a new public IP Natting with this new IP.
   
4. Create new website in the IIS with the following details
   

   Open IIS Manager MMC
   

   -Select Sites then right click and select “Add Web Site”
   

   
   

   -Fill the fields like this and click ok
   

   Site name: AutoDiscoverRedirect
   

   Physical Path: C:\inetpub\Autodiscoverredirect
   

   IP address: Select the 2^nd NIC IP address
   

   
   

5. Configure HTTP Redirect to the main autodiscover.domain.com url which is hosted providers’ domain.
   

   -Open IIS and Expand AutoDiscoverRedirect website then click on Autodiscover.
   

   -Double click on HTTP Redirect
   

   
   

   -Check the checkbox “Redirect requests to this destination”
   

   -Add the url “https://Autodiscover.domain.com/Autodiscover” and click ok.
   

       Example: https://Autodiscover.MSExchangeGuru.com/Autodiscover
   

   
   

6. Make sure to do it on all CAS servers.
   
7. Now time to configure DNS Which should have following records.
   

• Cname record
  

  Autudiscover.GO5LLC.com    AutoDiscoverRedirect.MSExchangeGuru.com
  

• Host Record
  

  AutoDiscoverRedirect.MSExchangeGuru.com    Public IP pointed to the 2^nd NIC
  

  AutoDiscover.MSExchangeGuru.com        Public IP Pointed to the 1^st NIC which is the IP of the default Autodiscover IIS VDir.
  

    8. This is the similar configuration as Microsoft Office 365 except Microsoft

 

 

 

 

 

 

 

 

 10. I am still trying to figure out how Microsoft is blocking port 443 and redirecting together. I will update the block once I will figure this out. I think Port 443 is blocked and port 80 is open for the AutoDiscoverRedirect IP. I have to ask network team to do it to get the same results  

We Blocked port 443 for the Public IP which is resolving to AutoDiscoverRedirect.MSExchangeGuru.com but allowed port 80. This is the most important step. This is suppressing the popup. After this popup stopped.

Now you might get this popup which is expected warning.

There are 2 options. Either check the checkbox “Don’t ask me about this website again” then click allow. Then it will not come again.

Or

Configure registry for all users as mentioned in the Microsoft KB here. https://support.microsoft.com/en-us/kb/2480582

Summary:

So you need the following to configure it.

2 Public IP – 1 with port 443 and other with port 80

2 Internal IP – 443 nat to Autodiscover and port 80 nat to AutoDiscoverRedirect

Public DNS – AutoDiscover host record map to the IP with port 443 and AutoDiscoverRedirect host record map to the IP with port 80

We will create the new website with the name AutoDiscoverRedirect on port 80.

 

 

This is not hard configuration and does not require any IISreset, service or server restart.

 

Prabhat Nigam

Microsoft MVP | Exchange Server

Team@MSExchangeGuru

Posted December 14th, 2015 under Autodiscover. Tags: Suppress Autodiscover Popup
RSS 2.0 feed. Leave a response, or trackback.