Tip#1: Lync Internal and External AutoDiscover DNS records
Tip#2: Lync Web services FQDNs
Tip#3: Lync Web services DNS records
associated with the external Web Services FQDN. Therefore, regardless of whether a mobile device is internal or external to the network, the device always connects to the Lync Server 2013 Mobility Service externally through the reverse proxy"
- The internal web FQDN must only resolve to and be accessible from inside the corporate network.
- The external web FQDN must only resolve to and be accessible from the Internet.
- For a user who is inside the corporate network, the Mobility Service URL must be addressed to the external web FQDN. This requirement is for the Mobility Service and applies only to this URL.
What is not obvious from the above statements are that for a DNS split-brain environment with mobile device clients connecting wirelessly, you need to configure the external web FQDN in the internal DNS with the public Reverse Proxy IP address. Otherwise, internal clients will not be able to reach the external web FQDN returned by the internal autodiscover service. Without this record, the mobile client will display an error "Can’t connect to the server. It may be busy or temporarily unavailable. Please try again" and you will likely encounter the error logs from the mobile client showing something like this:
"... The AppliesTo element of web ticket request points to a different web server or site... "
Tip#4: Reverse Proxy Web Listener
◦ Select Forward the original host header instead of the actual one.
◦ Select Requests appear to come from the Forefront TMG computer.
◦ Select Web server.
◦ Select Redirect requests to HTTP port, and type 8080 for the port number.
◦ Select Redirect requests to SSL port, and type 4443 for the port number.