Jurnal Ilmiah Teknik Elektro Komputer dan Informatika (JITEKI) Vol. 6, No. 1, June 2020, pp. 54~67 ISSN: 2338-3070, DOI: 10.26555/jiteki.v16i1.17105 54 Journal homepage : http://journal.uad.ac.id/index.php/JITEKI Email : jiteki@ee.uad.ac.id Analyzing challenging aspects of IPv6 over IPv4 Shahzad Ashraf* 1 , Durr Muhammad 2 , Zeeshan Aslam 3 1 College of Internet of Things Engineering, Hohai University, Changzhou Jiangsu, China 2 Department of Information Systems Management, Pakistan Steel Mills Karachi Pakistan 3 Petroweld Erbil, Kurdistan Region Iraq ARTICLE INFO ABSTRACT Article history’s: Received 01 July 2020, Revised 15 July 2020, Accepted 25 July 2020. The exponential expansion of the Internet has exhausted the IPv4 addresses provided by IANA. The new IP edition, i.e. IPv6 introduced by IETF with new features such as a simplified packet header, a greater address space, a different address sort, improved encryption, powerful section routing, and stronger QoS. ISPs are slowly seeking to migrate from current IPv4 physical networks to new generation IPv6 networks. The move from actual IPv4 to software-based IPv6 is very sluggish, since billions of computers across the globe use IPv4 addresses. The configuration and actions of IP4 and IPv6 protocols are distinct. Direct correspondence between IPv4 and IPv6 is also not feasible. In terms of the incompatibility problems, all protocols can co- exist throughout the transformation for a few years. Compatibility, interoperability, and stability are key concerns between IP4 and IPv6 protocols. After the conversion of the network through an IPv6, the move causes several issues for ISPs. The key challenges faced by ISPs are packet traversing, routing scalability, performance reliability, and protection. Within this study, we meticulously analyzed a detailed overview of all aforementioned issues during switching into ipv6 network. Keywords: QoS, Networking, mitigating, interoperability, VPN. This work is licensed under a Creative Commons Attribution-Share Alike 4.0 Corresponding Author: Shahzad Ashraf, College of Internet of Things Engineering, Hohai University, Changzhou Jiangsu, China Email: nfc.iet@hotmail.com 1. INTRODUCTION The fast Growing of Internet is taking place across the globe. After decades of struggle, due to speedy and appropriate technological advancement, a large number of technologies like 3G and 4G become a part of Internet which is supported for mobile devices. The fast changes of the Internet world enlarged the requirement for a unique IP address which can be used for individual devices. Benefiting from the services of Internet, the home users which are linked through smart phones can enjoy and take advantage from different services and the billions of IP addressing can only be provided through IPv4, 32-bit addressing technique which is about 4 billion [1]. The ISPs faced difficulties to provide Internet access to new users. Internet Assigned Number Authority (IANA) mentioned that IPv4 addresses are approximately ended [2]. The solution is to move on to the new IPv6 network. IPv6was developed by Internet Engineering Task Force (IETF) with extra features, such as smaller header size, larger address space, new any-cast addressing type, integrated security, efficient routing, and better QoS [3]. It is a 128-bit architecture and can provide undecillion IP addresses. It is said to be a next- generation IP protocol. Both IP4 and IPv6 protocols are different in format and behavior and cannot communicate directly with each other. ISPs are moving towards Next Generation Network (NGN) [4], progressively and the changeover process is very sluggish due to billions of devices are working throughout the world. Therefore, it is not possible to replace the entire network with new IPv6 at once in a short span of time. According to a Google survey report, after over 25 years, the transition process is 25 % completed approximately. There are many reasons behind this slow conversion. The economic factor is also at a high rate. Hardware cost, more energy consumption, staff training, etc. altogether increases the economic cost [5]. The dual-stack technique and virtualized network architectures are introduced to overcome the financial factor.