Uttarakhand Open University, 2017. This work by Uttarakhand Open University is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. It is attributed to the sources marked in the References, Article Sources and Contributors section. Published By: Uttarakhand Open University 3 4 Index 1.1 INTRODUCTION .......................................................................................................................................... 8 1.1.1 HISTORY OF INTERNET ..................................................................................................................................... 8 1.1.1.1 Internet Addresses ........................................................................................................................... 10 1.1.1.2 DNS ..................................................................................................................................