Skype for Business Edge Server reset connection

I ran in to a problem with a new Skype for Business server 2015 Edge installation. I was not able to connect to the sip.domain.com from a webbrowser. The browser finds the server but the server closes the connection (RESET). Therefore clients cannot log in at all.

So i fired up wireshark on the Edge server. I see my IP connecting to the Edge external interface, but it will give the message: “Reset: Set”

Skype for Business environment running with just one Public IP

/

For quite some time I’m running a home lab, first on a big server (HP Proliant DL360) and since beginning of this year I have a Intel Nuc, saves a lot of energy costs 😂

• Domain Controller and CA on Windows 2016 Core Edition
• Skype for Business Front-End Server on Windows Server 2012r2 standard
• SQL 2014 std for monitoring and persistent chat on Windows Server 2016
• Exchange 2016 on Windows Server 2016
• Skype for Business Edge on Windows Server 2016
• IIS ARR (Reverse Proxy) on Windows 2016
• PBX on Windows Server 2016

This lab was great for testing purposes but the problem was always, no connection to the outside world with Skype because of the requirement for at least 2 external IP’s with the use of Skype for Business.