أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
Firewall on Machine A, the only possibility i know of.
The problem is caused by MachineA firewall. Well most of the time you hv to "penetrate into the firewall and allow inbound connection for the port" ordinarily you can just off the Pc firewall or the antivirus firewall but it's not a recommended solution.