We have already discussed three private ranges used in classful and classless subnetting. The list does not stop there. This post identifies six types of special IP addresses that you will encounter. By the end of this post, you should have a clearer understanding of how these addresses are used in troubleshooting, how they appear on certification exams, and how they shape the way traffic moves across the Internet. 1. Loopback Address (127.0.0.1) Every networked device has a loopback address. Most commonly, it is 127.0.0.1 . The loopback address is typically used to test internal connections. You may wonder, “Why do I need to know if my device can connect to itself? Shouldn’t it connect to other resources and the Internet?” Think about it this way. Before you walk out the door, you make sure you look presentable by taking a shower, brushing your teeth, ironing your clothes, and checking yourself in the mirror. Once everything looks good, you are ready to go. Similarly, your compute...