What will happen if we ping the inside global address in a NAT system?
When I tried it was a success. But what exactly happened here? Did the NAT server replied or the packet was sent beyond the NAT server? If it was sent beyond the NAT server then who replied??
You are correct, this situation will work when you are talking about a static NAT only, with static NAT, a translation is statically configured and is placed in the translation table without the need for any traffic, and they remain in the translation table until you delete the static NAT command(s). While with dynamic NAT, the translation table in the router is initially empty and gets populated once traffic that needs to be translated passes through the router (IP + port) which is not available in the case of pinging, also dynamic translations have a timeout period after which they are purged from the translation table.