First you must distinguish between Public IP address and Private IP address. Your public IP address is that which the world believes you are on. Your PC private IP address may be something else entirely.
You may find your public IP address by using the BroadbandReports IP tool: /ip.
Your private IP address is that reported by your PC. For example, in Windows,
Start->Run->Winipcfg (or "ipconfig /all in a command line window)will bring up a utility that describes the IP address the PC has. Be careful, your PC may have several IP addresses!
If you cannot ping your public IP address, it may be because the machine this represents simply does not respond to ping.If you cannot ping your private IP address, you may have installed a firewall that refuses to acknowledge ping packets.
If neither of these cases apply, you may not have correctly identified your public or private IP address.
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