just change my modem (Vodafone-H-300s-v1.0.09.01_dsp190325T006) and I had a tremendous problem.

I have 2 desktops (win 10) connected to same network. The first(PC1) one has two servers (SQL Server and IIS). I noticed that I can't access from PC1 remotely to SQL Server and IIS Server.

So if I try to connect with DomainName (I use https://www.noip.com/) or my external ip, I can't connect from this PC. The strange fact is that I can connect from another desktop (PC2) remotely or even from my laptop or phone with WIFI (same network) or data.

Experiment: I create a test website in PC2 with iis and I noticed that the same problem exists. I can't connect from PC2 with DomainName but I can connect from PC1 to PC2 remotely.

SO I CAN'T CONNECT REMOTELY FROM THE PC THAT HAS THE SERVERS.

And this is problem because on PC1 the website in IIS Server tries to load data from SQL Server which is installed on the same PC1.

I am quite sure that the modem is responsible for this and the port forwarding because it happens in both desktops.

I use for my website port 7500 and SQL Server 1433.

Static ip for pc1 192.168.1.100.