After installation another Lync Frontend Server, in this case a SBS. The Federation was broken.
Incoming via the Edge Server everything looked fine. Meaning, incoming Federation request, e.g. presence or IM, as well as remote access from users hosted on this SBS were working correctly.
But all outing communication to federated partners didn't work at all.
After using the OCSLogger and analyzing the logs in SNOOPER, I saw an error message: The peer is not a configured server on this network interfaceandSIPPROXY_E_CONNECTION_UNKNOWN_SERVER
coming along with another message: winsock-info="The peer forced closure of the connection"
I used the RUST tool internally verifying the SBS certificate, it was correct. Even requesting the certificate again didn't help at all. Even I imported the Topology on the Edge server again!
What this clearly explains was, if the SBS was presenting it's certificate, it didn't work. If the Edge Ser…