Suppose I have a router with this valid IP address (it's not real): 188.8.131.52
So this router is identified by this ID. The internet is available through this router.
Another computer wants to access 184.108.40.206 over internet, But because 220.127.116.11 is set in router, it never sends the request over internet and Immediately shows 192.168.0.5
I want to see 18.104.22.168 via internet, But because router is intelligent(!) it doesn't send client's request to ISP.
I know that ISP only identifies a valid IP address, But router doesn't reply to the request through the internet.