Certificate error on the second exchange that is used as a proxy for internet facing

Question

Hello friends ,
I have one just like it ( http://faragesolutions.files.wordpress.com/2013/04/proxy.jpg?w=650 ) scenario . Using two Exchange , only one of them is accessed as a proxy .
In Exchange that is facing internet , I use a digital certificate with the public domain ( webmail.name.com ) and my OWA is configured to ( External: webmail.name.com ) and Internal : webmail.name.com ) .
You Exchange that are not face to internet , OWA is configured to ( External: empty) and ( Internal : servername.local ) . This Exchange user when connecting with Outlook client is generating validation error name ( servername.local ) , because as I'm using
the same Exchange certificate that is facing internet . So the audience is trying to validate the certificate name that is not registered as an alternative name.
question : the exchange that is not facing the internet, I need to use the same public certificate that is in exchange that is facing the internet? or can I just use an internal certificate?
Thank you.

Answer 1

The names that go on the certificate must match the names you planned when you did the CAS namespace design.
Some details here:http://blogs.technet.com/b/exchange/archive/2014/02/28/namespace-planning-in-exchange-2013.aspx
So in your case if the cert does not match the name, then this will prompt users with errors.   They need to match.  As long as all your internal devices trust the issuer of the internal CA then you can use that.   Installing an
enterprise CA will automatically publish it's root CA  public cert into AD so it works easily.
Cheers,
Rhoderick
Microsoft Senior Exchange PFE
Blog:
http://blogs.technet.com/rmilne 
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