* Description: Knowledge of network public and private IP
* Compatiablity: RDBMS 11g, 12c
* Date: 05:58 PM EST, 05/15/2017

<1> Network Public IP:
     |__ A public IP address is an IP address that your home or business router receives from your ISP. 
         Public IP addresses are required for any publicly accessible network hardware, like for your home router as well as for the servers that host websites.
         Each and every device that's accessing the internet is using a unique IP address. In fact, a public IP address is sometimes called an Internet IP.

<2> Network Priviate IP:
     |__ It's a unique identifier for all the devices behind a router or other device that serves out IP addresses. However, unlike with public IP addresses, the devices 
         in your home can have the exact same private IP addresses as your neighbor's devices, or anyone else's all around the world.
         This is because private addresses are non-routable - hardware devices on the internet are programmed to prevent devices with a private IP address from communicating 
         directly with any other IP beyond the router that they're connected to. Because these private addresses are restrained from reaching the internet, you need an address 
         that can reach the rest of the world, which is why a public IP address is needed.

         This type of setup enables all the devices in your home network to relay information between your router and ISP using just a single address - a public IP.
<3> Public IP is analogy with street address are shared by all the suites in a building. Private IP is the room number.

<4> How to find your public IP - http:\\whatismyipaddress.com		 

<5> Dynamic IP:
     |__ Most public IP addresses change, and relatively often. Any type of IP address that changes is called a dynamic IP address.
         Back when ISPs were a new thing, users would connect to the internet for only a short amount of time, and then disconnect. 
         An IP address that was being used by one customer would then be open for use by another that needed to connect to the internet.

         This way of assigning IP addresses meant that the ISP wouldn't need to purchase such a large number of them. 
         This general process is still in use today even though most of us are always connected to the internet.

         However, most networks that host websites will have static IP addresses because they want to make sure that users can have constant access to their server. 
         Having an IP address that changes would defeat the purpose, as DNS records would need to be updated once the IP changes, which might cause unwanted downtime.

         Home networks, on the other hand, almost always are assigned dynamic IP addresses for the opposite reason. 
         If an ISP gave your network an unchanging address, it may be more likely to be abused by customers who are hosting websites from home. 
         This is one reason why having a static IP address is more expensive than having a dynamic IP address. DDNS services, which I mentioned earlier, are a way around this... 
         to some degree.

         Another reason most networks have public IP addresses that change is because static IP addresses require more management, and therefore normally cost more for 
         a customer to have than a dynamic one. For example, if you were to move to a new location a few miles away, but use the same ISP, having a dynamic IP address 
         assignment would simply mean that you'd get another IP address that's available from the pool of addresses. Networks using static addresses would have to be 
         re-configured to apply to their new location.

<6> Reference:
     |__ https://www.lifewire.com/what-is-a-public-ip-address-2625974


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