Hi - I have an existing 2010 environment of 2 CAS servers and 2 mailbox servers. All external URLs are set to mail.contoso.com and all internal URLs are set to mail.contoso.com. The CASArray is mail.contoso.internal.
I want to keep all my URLs the same for 2013. So I will install Exchange 2013 and set all the external and internal URLs on my 2013 environment to mail.contoso.com
That sounds simple enough and so now I re-point my external and internal DNS records for mail.contoso.com to the new 2013 environment. Is this going to work?
I have looked at how 2013 proxies or redirects to the 2010 environment it seems to suggest that everything is proxied which sounds good. However, I saw this article http://michaelvh.wordpress.com/2012/10/09/exchange-2013-interoperability-with-legacy-exchange-versions/ which suggests that 2013 will only proxy is there is no external URL set on the 2010 servers. In this case there still will be - it will be mail.contoso.com. Do I need to remove the external URLs on my 2010 servers?
And one last thing regarding the article above, it says that Exchange 2013 does some clever stuff when proxying, it doesn't use the internal URL and instead builds a URL from the CAS server name. Is that correct? the problem I'm anticipating if that is the case is that I do not have the 2010 cas server address on my certificates - I only have mail.contoso.com.
If anybody could clarify this process that would be great - I would have thought that the majority of people would want to migrate keeping their URLs the same - but the documentation doesn't seem to confirm whether anything needs to be changed on the 2010 environment. Thanks