The problem: I've installed Windows Server 2019 and I am trying to discover my WCF services running on a Windows Server 2012R2. But that's not working and in Wireshark I see a ICMP Destination unreachable (Port unreachable).
My current Infrastructure
We have some old Windows Server 2012R2 where the WCF Services are running and when I try to discover them from some other Windows Server 2012R2 that I can discover them without any problems.
The Windows servers are all installed on virtual machines which are all in the same network and no firewall is between them, the windows firewall is disabled with group/domain policies.
I've installed wireshark on my Windows Server 2012R2 where my WCF Services are running ip: 172.30.40.2 On this machine I've filtered in wireshark with "ip.src==172.30.40.31 or ip.dst==172.30.40.31" the IP from my Windows Server 2019 is 172.30.40.31.
I've also installed wireshark on my Windows Server 2019 and here I see the same as shown in the picture.
As far as I know shows me the ICMP message that there is a problem, but I am not shure how to read it right. Where is the problem is the Source multicast port 3702 not reachable or the other port 65116? Is the problem on my Server or Client?
Very intresting is, when I restart my windows Server 2019 an I have a test client to check the discovery then mostly the first time I try to check the discovery it works but when I try it again its not working anymore only after restart its working again for one discovery.
I am not shure which informations I could provide to get a hint where I could search to resolve this strange issue.