Often we have to troubleshoot routing and firewall rules as seen from a client on a internal client subnets. I use PSEXEC and PORTQRY from Microsoft. This will work if it is a Windows pc and I have permissions to connect to it. Run these commands from a server in the server lan

I try to check if the port is open from the client to server (10.10.10.100) :

PsExec.exe
\\clientpc.domain.local -c portqry.exe
-n 10.10.10.100 -P TCP -e 443

If this fails I will run a tracert from the client to the server IP (10.10.10.100):

PsExec.exe
\\clientpc.domain.local tracert -h 8 -d
10.10.10.100