Analyzing challenging aspects of IPv6 over IPv4

Shahzad Ashraf, Durr Muhammad, Zeeshan Aslam
2020 Jurnal Ilmiah Teknik Elektro Komputer dan Informatika  
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
more » ... 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 coexist 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. Network Functions Virtualization (NFV) [6] , is a new concept and an emerging network technology introduced. The primary objective of NFV is to eliminate hardware resources and provide networking services like routing, firewall, DNS, DHCP, etc. through a software-based virtual machine. Whereas in the dual-stack technique, new devices are supported to both functionalities of IPv4-IPv6 and can be communicated with both protocols easily. To support the IPv6 in the future, it is needed for ISPs to develop an independent and parallel IPv6 network with IPv4. It means, both protocols will co-exist for a long time during the transition. By nature, the network topology is hybrid. The addressing method, compatibility issues and operation methods of IP4 and IP6 are totally different [7] . Though, it generates a lot of problems for ISPs to translate IPv4 addressing techniques to IPv6 Network. During changeover, it creates the issues like security, traversing of packet, scalability and some performance related problems faced by ISPs [8] . In Traversing of packet, the data communication is done by two IPv6 networks over an IPv4. For resolving such issues, the technique introduced is called Tunneling [9] . This technique is the only solution. The end nodes in tunneling implement dual IP layers in host and router means support both IPv4 and IPv6 architecture called dual stack router. There are many techniques used in tunneling called static and dynamic [10] . In such techniques, static is suitable to implement while others are not in practice due to performance issues. Routing is also a challenging task for network professionals when the network size is large, complex, heterogeneous, and scalable. Without a proper scalable routing system, a network does not provide better performance. The scalable routing system determines the best path from source to destination quickly and efficiently if multiple paths exist in the large and complex network. Routing protocols are introduced to overcome routing and scaling issues. A variety of routing protocols is available for both IPv4 and IPv6 networks. IPv6 routing protocols are different from each other in terms of configuration, metrics, convergence speed, and other functionalities over IPv6 tunnels [11] . In any data network the main risk is security. Even though, the header of IPv6 offers incorporated security features which is able to decrease the Network threats, but still uncovered by many attacks i-e Internet Control Message Protocol for IPv6 attack, Header attack for IPV6 and Reconnaissance Attack. The influence of some identified IPv4 attacks are not changed its appearance for new IPv6 protocol. While, the attacks like sniffing, flooding, man-in-the-middle-attack (MITM) [12] , can affect the both IP addressing techniques (IPv4 and IPv6). To reduce the security threats and minimize the risk, there is required to change and design strong Network policies, and install some monitoring systems and implement some security tools like firewalls and IDS for external threats. The network functions which can be offered for NFV in case of firewalls, Storage Systems, Virtual Private Network (VPN), Gateways, DHCP and Domain Name Service (DNS) etc. can implement security in the course of software, not for hardware based. The NFV architecture is comparatively reliable than traditional architecture which can be suited for energy consumption, for some hardware, operating reliability, cost of equipment and deploying of network topology [13]. COMPARISON BETWEEN IPV4 AND IPV6 HEADERS The Internet Protocol is routable protocol over the Network. There is no surety to deliver a packet by IP. In fact, the IP Address tries its best to deliver a packet over the network in best possible way through different routes [14] . Some application protocols such as FTP, SMTP, and HTTP have required a guarantee of packet delivery. To provide a guarantee of packet delivery services, the IP protocol is associated with TCP protocol on the transport layer. The packets are moved on the network in an arbitrary path if multiple paths exist. On the networklayer, a segment is encapsulated by an IP header before sending. Source and destination IP addresses are enclosed in an IP header. The IANA has declared some blocks of IP address from different classes for private networking [15] . The 169.254.0.0/16 address reserved for link-local addressing. All the reserved and private addresses are not routable over the Internet. The NAT was introduced to provide Internet access for private networks [20]. IPv4 Header The majority of Network traffic is based on IPv4. In IPv4 packet, header and data unit is part of that packet. Before transmitting the packet over the network, the header of minimum 20 bytes is encapsulated with the Data Unit part of IPv4. The IPv4 header consists of 14 fields. Its maximum size is 60-bytes. One field is optional. The first4-bits of the header are version. It indicates the IP version used. A TTL8-bits field helps stop the packet from moving in the loop on the Internet. Every time when a packet arrives and crosses one node on the network, then its TTL field is decremented by one [16] . When the TTL field becomes zero, the node discards the packet. The header checksum 16-bits field is used for error checking of the header. When a packet reaches the router, the checksum of the header is calculated by the router. The router compares both values. If the value does not match, the router discards the packet. The32-bits source and destination IP 56 Jurnal Ilmiah Teknik Elektro Komputer dan Informatika (JITEKI) addresses fields are used to store the sender and receiver IP addresses respectively. These addresses may be changed in transition by NAT devices. About IPv6 Header The most recent version for IP addressing is IPv6 which is supposed to be used for coming generation. It is called 128 bit addressing architecture. Its total IP addresses can be calculated in 2 128 , almost 3.4 x 10 38 total IP addresses. Most repeated zeros can be reduced to double colon [17] . Because of large addressing volume, there is not necessary for Network Addressing Translation. But some Addresses range can be reserved by its standard IANA. In IPv6, a new multicast implementation technique has introduced. A new feature Stateless Address Auto Configuration (SLAAC) is introduced in IPv6 to eliminate additional configuration servers. It allows a host to generate own address using a combination of link-local address and information advertised by routers. IPsec is used as a built-in security feature in IPv6 with the help of the extension header [18] . It is a mandatory part of all IPv6 protocol implementation. The extension header carries optional information along with the IPv6 header. The extension header provides support for fragmentation. There are several types of extension headers. The IPv6 header is simplified. Some fields are removed. It consists of only 8 fields. Its size is fixed and that is 40-bytes. The first4-bits of the header is also version same as in IPv4. The TTL field is replaced with the 8-bits Hop Limit field. The Next Header 8-bits field in the fixed header indicates the type of the extension header. The size of the source and destination IP addresses fields are increased to 128-bits. The Flow Label20bits field provides traffic engineering and QoS services. Jurnal Ilmiah Teknik Elektro Komputer dan Informatika (JITEKI)
doi:10.26555/jiteki.v16i1.17105 fatcat:54mngzpyfber5kf6w2luu7nnfa