HyperV replication true port 443

Hi,

I had HyperV replication for a few virtual machines sucsesfully installed and up and running.

i configured port 443 for the replication and i use self signed certificates.

suddenly a few weeks ago the replication stopped with an error. I did find out that port 443 is not listening anymore on the replication server with the error. Even a port scan to the localhost replies with 'filtered'.

A port scan of port 443 on an other HyperV replication server is sucsesful

So my question : why is port 443 not responding ? what services are responsable for the hyperv replication ?

Thx

Koen