Our unit all the computer to the switch, switch and received on a router, through a public IP access to the Internet, my own computer IP for 192.168.20.161
According to TCP/IP protocol, when I visit public website, my computer IP packet encapsulation of the two, one is my source IP 192.168.20.161, the other is a remote target server's IP, and in the transit packets encapsulation of both IP won't change,

That excuse me: my computer access to specialized query the IP address of the site, why do we display unit public IP? According to the TCP/IP protocol, packet encapsulation source IP and destination IP in transit will not change, so why public IP will be shown?

I was wondering, I see information, when the router to forward packets, packet source IP and destination IP should be always the same, just hardware address, can I visit public website, my computer send packets through our unit of router, the router will be the source of the packet IP192.168.20.161 public IP to our unit?