Internetworking IpV6 vs IpV4: Compare and Contrast - Research Paper Example

? Internetworking IPv6 Vs IPv4 (Section) Due) A new version of the internetworking protocol, IPv6, was designed to address the service and scalability shortcomings of the previous version, IPv4. Unfortunately, machines and systems designed to one protocol cannot directly communicate with another machine designed to the other protocol due to the incompatibility between the two protocols. Changing from one protocol to the other would require software changes in all the networked devices. This calls for a smooth transition from the lower version (IPv4) to the higher version (IPv6) protocol to allow applications to continue working as the upgrade is done gradually since IPv4 is the dominant network layer protocol. But until then both the internetworking protocol versions will operate simultaneously in the network with the networks using IPv6 having the ability to support both IPv4 and IPv6 addressing. (Minoli,2008) The paper analyses the similarities and differences that exists between the two versions of internetworking protocol; IPv4 and IPv6 while stating their major characteristics, advantages as well as their limitations. It finalizes by making a conclusion based on the comparison. Introduction Internet protocol version six (IPv6), according to Minoli, is an internet protocol developed with the intentions of succeeding the previous version, IPv4. It was developed with the limitation of the previous version put into consideration. The rapid growth of the internet has outgrown the capabilities of the IPv4 as an internetworking protocol given the fact that its development is dated back to 1981.Its addressing capabilities for example, with an addressing space of 4 billion, has been outweighed by the growing number of devices requiring permanent allocation of IP addresses. (2008) Goralski states that the original design of IPv4 lacks certain functionalities that are involved with mobility, quality and security since it was designed many years ago. It therefore require additional protocols to enable it handle the functionalities since they are not integrated within the protocol itself. In addition to the addressing space problem and the missing functionalities, the growing number of elements in the routing table called for the development of a higher version of the internetworking protocol, IPv6. The IPv6’s main characteristics including lager addressing space, simplified routing, automatic configuration and improved security, were designed to aid in solving the problems that exist in the previous version, IPv4. (2009) The comparison of the two protocols will be done based on their abilities to deal with the challenges in today’s internet and other factors as well. There are several challenges facing internet in today’s world due to its fast and rapid growth over the years including increasing security and information protection, address depletion, increased traffic flow, loss of peer to peer model, burdened infrastructure and increasing need for IP mobility among others. (Minoli, 2008) Addressing space The two internetworking protocol versions differ mostly in their addressing mode and the number of addresses each allow with IPv6 capable of addressing more addresses than the lower version, IPv4.According Joseph, basically IPv6 has an addressing space of 128 bit whereas IPv4 has only an addressing space of 32 bit, that is, almost four times longer than the addressing length of IPv4. Meaning that IPv6 has an addressing length of two power 128 (2128) resulting to an addressing possibilities of up to 3.4 x 1038 while IPv4 having an addressing possibilities that is as low as 4.3 x109 (4,294,967,296 possible addresses). (Shima, 2007) Shima argues that as opposed to IPv4, IPv6 has a much larger addressing pool and is able to accommodate the increasing IP addresses even in the future. Network devices that require IP address allocation are constantly on the rise with mobile phones taking the lead among other communication devices. Future household appliance will be networked enabling access and control through networking and therefore calling for more addressing space which can only be handled by the IPv6 networking protocol since it has the addressing capability as compared to the previous version, IPv4.(2007) The addressing space of IPv4 is almost depleted with up to ninety percent of the addressing space used by the ever growing network devices which must be allocated an Internet protocol address for proper routing. It is clear that at some point IPv4 will run into address exhaustion point where there will be no more available addresses to locate to new networking devices in the future. IPv6 on the other hand employs a 128 bit addressing space, 64 of which are for network identification and the remaining used for host identification. This eliminates the main problem existing with IPv4 version (the inevitable exhaustion point) being that it is almost impossible to deplete the number of address space offered by IPv6. (Shima, 2007) Headers According to Asadullah, even though IPV6 has an enlarged header, twice as large as the header in IPV4 with a four times a IPv4 address, its header is still considered simpler than that of IPv4 since there are some features in the IPv4 header that are either made optional or dropped in the current version, IPv6. (2009). He adds that the length of the header in IPV4 is 20 bytes while the one for IPV6 is 40 bytes. As IPV4 migrates to IPV6, the number of headers increases while the number of the header fields reduces specifically from 12 to 8 in order to eliminate redundancy. In IPV4, some of the routers fragment packets for easy transferability to their destinations in the network. (2009) The number of byte for each IP address has been increased from four bytes for each address in IPv4 to sixteen bytes for every address in IPv6. This means that a larger part of the header is used to represent IP addresses in IPv6 as compared to IPv4. The option field in the base header in IPv4 has been removed in the current version IPv6 in order to eliminate the header length since the header will always have the same length. (Manepalli, 2009) IPV6 does not support packet fragmentation, so in that sense, the number of headers reduce by some of them becoming useless to eliminate redundancy in IPV6. In IPV4, the header fields are aligned to 32 bits while in 1PV6 the header fields are aligned to 64 bits. 64 bit header fields contain microprocessors and microcontrollers to support easy processing. Support for multiple headers including upper layer headers is another characteristic of IPv6 that is not available in IPv4. The support for multiple headers in Ipv6 allows it to provide for feature enhancements unlike the previous version, Ipv4. Furthermore all the additional or optional information is processed in encoded in extension headers. There is a big difference in the header fields of both the IP versions most of which have been changed from the lower version to better reflect their functions and others eliminated in the new version. The total length in the IPv4 header is replaced by payload length in IPv6 header. The field originally “Time to live” in IPv4 header has been replaced by “Hop limit” in IPv6 to better reflect its function. Protocol field in IPv4 has been changed to next header in IPv6. The main reason for the decreased header fields in IPv6 is to reduce the unnecessary redundancy provided by most of the header fields in IPv4 for instance the checksum field in IPv4 which is not present in IPv6. The checksum functionality, to ensure header integrity, can be achieved through some other mechanisms such as formation of packets which has frames that contain the same functionality. The fragment offset header in IPv4 is completely useless in IPv6 calling for its elimination in the IPv6 header since the two IP versions have completely different fragmentation. The difference in fragmentation is due to the fact that routers using IPv6 do not fragment neither do they defragment data packets during transmission. (Manepalli, 2009) IPv6 therefore has the following header fields most of which do not exist in the previous version, IPv4. Version field: indicating the version of the IP protocol being used with a value of 6 and length of 4 bits, Traffic class field: shows the kind of traffic used including the priority, Flow label, Payload length and Next header. Generally the header format has been simplified, meaning that Ipv6 has a simpler and less redundant header as compared to IPv4. Mobility Bernardos states that In recent network technology development, wireless technology such as Bluetooth, WLAN, and GPRS were implemented to improve on mobility of users as people will be able to move freely. Mobility function in a networking protocol should allow nodes to remain reachable and connected while moving around or stationary. Handset devices and laptops are example of mobile nodes since their users are always in constant motion but at the same time need internet connectivity. A mobile node is always associated with a care-of address which provides information on the mobile node’s current location whenever the node is away from its home address. (2012) IPv6 has the functionality that enables transparent routing of packets which are addressed to a mobile node’s home address to its care-of address. The Mobile nodes using IPv6 are able to cache the binding of their home address with its care-of address thus sending any packets destined for them directly to them at the care-of address. (Goralski, 2009) According to Jinmei, IPv6b provides an improved mobility support as compared to IPv4 enabling mobile nodes to remain connected irrespective of their location where on motion or stationed. It allows the mobile users to change their access point while remaining connected at the same time better than IPv4. The mobile support is integrated in the IPv6 protocol since it was taken into account in the design phase of the protocol unlike the IPv4 which has the function supported as an external patch. (2004) Koodli argues that Handset devices in IPV4 would require an external help to link to a network or an access point. IPV6 provides a mobility advantage of allowing handset devices to access an address from a foreign network without any external help. IPV6 implements mobility protocols within the standard protocols unlike IPV4. IPV4 uses the triangle mode where a correspondent node sends packets to the server (HA) which then sends them to a mobile node. IPV6 allows the correspondent node to send packets directly to the mobile node. (2007) The method used by IPV4 to send the packets is an encapsulation method as the packets move from a correspondent to server then to the mobile node. This creates a lot of communication overheads which can be reduced by implementing routing header to channel delivery of packets to their respective destinations. IPV6 uses the routing header for packet delivery. The use of routing headers is a remedy to communication overheads. (Manepalli, 2009) Security IPV4 relies on end to end host to provide security during communication. It does not include the security in its normal TCP/IP suite. The following are some of the security threats in IPV4: Reconnaissance: This is a method of attack whereby the attacker tries to learn about the network of the victim as much as possible before an actual attack is made. This can be done either though active network methods such as scanning or passive data mining method through search engine or public documents. In the active network method avenues of attach are done based on the information about the host and the devices connected I the victims network, previously collected. (Amoss,2008) Ammos adds that In IPv4 the attacker has more opportunity for conducting this type of attack on a network as compared to IPv6. IPv4 provides several methods such as ping sweeps and port scans which are easily used by the attacker to carry out an attack. The attacker can succeed by simply determining the IPv4 address used in the targeted network from which he then carries out his attack with ease as compared to IPv6.(2008) IPv6 provides a hard time for an attacker using this method of attach since its ping sweeps and port scans are much more difficult to complete when used to enumerate the victims address as opposed to IPv4. Reconnaissance technique is however the same in both IPv4 and IPv6 beyond the two differences in addition to the fact that IPv6 networks are even more dependent on ICMIPv6 to properly function as compared to IPv4. The dependency of IPv6 on ICMPv6 predisposes it to threat since aggressive filtering of ICMIPv6 has a negative effect on the network function. Unauthorized access is another example of an attack where the two IP versions differ. In this method of attack, the attacker tries to exploit open transport policy mostly inherent in IPv4 protocol as compared to IPv6 protocol. The attacker relies on the fact that there is no limit to the set of hosts that can establish connectivity to another host on the IP network. The attacker is able to make a connection to the upper layer protocols and applications on the internetworking devices by utilizing this fact. IPv4 through access control technologies have concentrated on limiting the unauthorized access which only occur in layer 3 and 4 with the complexity increasing with the increase in stack. The need for access control technologies is similar for both IPv6 and IPv4 though easier host access control can be achieve through IPSec which is only possible in IPv6. (Bernardos, 2012) The basic function in mitigating access to other IP devices based on policy is still implemented through firewalling in IPv6 which is effective only in applying policy based information from layer three due to the cryptographic protections. IPv6 only uses the authentication header. Denial of Service IP Spoofing Is an attack on network security where an adversary masquerades or impersonates a given range of organizations IP addresses and gains access to organizations network. An IPV4 consideration on IP spoofing is to authenticate the source IP address. This consideration might not be very effective because many adversaries could channel their attack on one server, and hence the server may be unable to authenticate all source IP addresses due to scalability issues. (Shima, 2007) Viruses and worms Distribution Man in the middle attack Packet fragmentation IPV6 on the other hand uses the IPSec protocol to ensure security. The IPSec is a set of packets which ensure security at the internet layer of the TCP/IP suite. The IPSec uses two protocols to implement this security i. e the authentication header and the encapsulated security payload. The Authentication header ensures integrity and authenticity of packets but it does not guarantee confidentiality. The components of the authentication header are: Sequence number- The sequence numbers prevent the replay network attacks which involve passive capture of data and subsequent retransmissions to cause unauthorized effects. Sequence numbers ensure that packets are delivered at the right time. Security Parameter Index-These are the security association of information Message Digest-Used to ensure integrity of the packets sent Padding- Addition of meaningless information to a packet to maintain its size Schwartz adds that the Encapsulation Security Payload consists of the ESP trailer and the ESP authentication data. It ensures confidentiality, integrity and authenticity. It has the same components as the authentication header except for padding. ESP uses the ESP trailer to implement padding. (2012) Quality of Service IPV4 uses one field known as the TOS (Time of Service) to implement the quality of service. The TOS ensures that service is delivered at the scheduled time. IPV6 uses two fields to ensure quality of service. These fields are the traffic class and the flow label. The Traffic class replaces the TOS in IPV4. QOS tries to achieve the following goals: Reduction in packets latencys Fault Tolerance Timeliness of the packets transfer Tunneling According to McFarland, tunneling in IPV4 uses a gateway to gateway communication. A virtual path is created between the segments of different private networks. The path passes between a hostile network e. g the internet to another private network. The internet is used in the tunnel mode due to cheapness or reduced cost. In IPV6 is used as a technique to deliver packets through IPV4. The IPV6’s datagram are encapsulated in IPV4 before transfer so that the resultant network can be handled by IPV4 routing protocols. (2011) Configuration IPV4 uses a manual configuration or the Dynamic Host Configuration Protocol. The DHCP server for 1PV4 is used to allocate IP addresses to computers in a network. IPV6 on the other hand uses Universal Plug and Play with or without DHCP. In network configuration, IPV4 uses mainly manual and labor intensive while IPV6 supports the re-numbering of hosts and routers.( McFarland, 2011) Packets Transmission In IPV4, the packets can exceed the required sizes while implementing message integrity. The sending server encrypts the packet and then it concatenates the encrypted packet with the original packet. This makes the packet double in size. The problems related to this are: Doubling of packet sizes increases the bandwidth in a network hence causing downtime of servers Doubling of the packet sizes causes increase in communication overheads which slows down a network IPV6 includes a header plus a payload which does not exceed the required packet size because encryption of the packet is done using strong cryptographic algorithms supported by IPV6. These algorithms include MD5, MD4, SHA-1 and RSA. These algorithms are used by the sending server to compute a message digest which distills messages to a fixed bit length. It takes a variable of the length of the message and converts it to a standard 128 bit. This reduces the bandwidth data consumption and the communication overheads as well. Operating Systems Support Currently the basic operating systems supported by IPV6 are more that those IPv4 is capable of supporting and they include: Linux Sun Solaris 8 and 9 Windows 2000 and XP IBM AIX HP-UX 11i The above mentioned operating systems try to imitate packet features for IPV6 and some features like tunneling which uses IPV6 datagram in IPV4 routing protocols. IPV4 on the other hand is supported by all operating systems which try to implement interoperability during the process. (Shima, 2007) Hardware Support In IPV4, most hardware is supported for routing, and mobile devices. Hardware varies from a wide range of software-based applications and operating system environment. Some of the mobile devices supported by IPV4 are Nokia, NEC, Fujitsu, Erickson, Hitachi and Alcatel. Hardware supported also depends on the application environment and the operating system environment. In IPV6, currently most hardware involves routing only e. g CISCO. IPV6 varies between software-based and hardware-based packet forwarding. (McFarland, 2011) Application Support Number of IPV6 applications is growing. Below are some of the services used for both IPV6 and IPV4 and how they are implemented differently according to their features: DNS and some DHCPV6 Domain Name Servers (DNS) are mainly used to transform domain names to IP addresses for subsequent processing. IPV4 domain names are split into groups of 32 bits for IP addressing. IPV6 splits the domain names into 64 bits groups for IP addressing. IPV6 also implements DHCPV6 (Dynamic Host Configuration Processing Version 6) which allocate IP addresses to computers within a network. DHCPV6 is better than the normal DHCP for IPV4 in the sense that, DHCPV6 is more scalable because it can allocate IP addresses to a larger or an increasing number of computers. As for DHCP for IPV4, there is some fear of servers running out of IP addresses Web Servers and Web Browsers Most web servers support IPV4 features e. g incase the DNS server goes down, they are able to use the IP addresses to access the site. Some web servers do not support referencing to IPV6 IP addresses. In these particular cases, there is a high risk of server going down in case the DNS server fails to work. Most web browsers are also preconfigured to allow only the numeric values in the IP address text fields as well as the port number text fields. IPV6 uses hexadecimals and alpha-numeric to represent the IP addresses. The recent browsers like Google chrome are able to accommodate that.( Minoli,2008) Emails In IPV6, the server client availability is not there unlike in IPV4, the mail servers have a provision for the server and the client protocols. Proxy Gateways Firewalls Perkins states that In IPV4, most applications support the circuit level proxy gateways where the TCP/IP circuit maintains connection on behalf of the client. TCP/IP circuits maintains a connection between the inside host and the proxy gateway and between the outside host and the proxy gateway. The main disadvantage of circuit level proxy gateways is that when one port is in use, the other ports remain open, which is susceptible to attacks by intruders in a network. The only advantage of the circuit level is that it is cheap as it does not incorporate sophisticated technologies. (2007) In IPV6, most applications support the application level proxy gateways where most proxy technologies are incorporated e. g HTTP, FTP, TELNET and SMTP. Application level proxy gateway has the advantage that: -It is more intelligent than the circuit level -When one port is in use, the other ports are closed -It maintains log files which records data about packets travelling within a network. The log files are able to identify the stray packets within a network, inbound and outbound packets. ISP Deployment Shima argues that most ISPs only support IPV4 because they are driven by customer demand. ISPs are also required to get a regional prefix for provision of IPV6 before they commence. Obtaining the regional prefix is quite expensive because few organizations use the IPV6 technology. ISPs using IPV4 are very stable marketwise as they have a stable customer demand. Obtaining a regional prefix for IPV4 is not costly as most organizations want it. Conclusively, ISP deployment involving IPV4 appears to be simpler. (2007) Network Address Translation IPV4 uses organizations firewall features to implement NAT. Most organizations have private IP addresses which are very different from the public IP addresses. NAT is used when translating private IP addresses to public IPs or vice versa. NAT also does the translation of the port numbers. Information required by NAT is the source and destination IP addresses. This information is picked by the firewalls. IPV6 on the other hand can perform IP address translation more effectively and efficiently than NAT because it addresses some of the issues that NAT has: (Goralski, 2009) NAT breaks end to end model of IP NAT is not scalable enough to handle large networks Fast re-routing is impossible with NAT. Some applications don’t work with NAT NAT breaks the security There is need for a larger address space and in this case IPV6 is likely to replace NAT. Multicasting Support According to Goralski, Multicasting is the one to many transmissions of packets across a network. It involves the movement of packets from one computer to several other computers. IPV4 supports multicasting but at a limited level because it cannot accommodate increasing number of computers. In such cases packets would be lost or maybe they would be interrupted from reaching their destination.(2009) IPV6 on the other hand supports multicasting strongly because it is scalable and can accommodate an increasing number of computers in a network. IPV6 supports new multicasting address that can enable an adversary to identify key resources on a network and attack them. Internal address use in IPV6 should be filtered at the border and should not be reachable from the outside. (Goralski, 2009) Network Management tools Currently there are no ping sweeping tools for IPV6. Nmap is present for IPV4 and hence IPV6 does not support ping sweeping. Also most IDS detection systems do not support IPV6, making it hard to detect scanning activities. On the other side, newly developed firewalls are able to allow filtering of unwanted packets on both IPV4 and IPV6. IP Spoofing Considerations Is an attack on network security where an adversary masquerades or impersonates a given range of organizations IP addresses and gains access to organizations network. An IPV4 consideration on IP spoofing is to authenticate the source IP address. This consideration might not be very effective because many adversaries could channel their attack on one server, and hence the server may be unable to authenticate all source IP addresses due to scalability issues. (Asadullah,2009) An IPV6 consideration on the other hand would ensure regulation of IP spoofing at an ISP level whereby filtering takes place at the ISP so that an ISP confirms that the customers are not spoofing. IPV6 layer 4 can also filter a large number of adversary attacks due to its subnet features. The subnet for IPV6 is quite large to allow for this. Conclusion IPv4 which is the first version of the internet protocol to be widely deployed is the fourth iteration of the internet protocol and most dominant network layer protocol on the internet mostly used beside the higher version, IPv6. It is a data-oriented protocol to be used in a packet switched network like Ethernet using a best effort mechanism as a routing protocol since it does not guarantee delivery. Ipv4 does not make any guarantees on the data correctness which may results into duplicated packets and or out of order packets. All of these limitations among others are addressed by upper layer protocols like TCP and UDP which it uses as external patches. Basically, Internet protocol main function is to provide a unique global computer addressing in order to ensure that there is no conflict between two or more computer by ensuring a unique identification mechanism. IPv4 though still widely used is roughly over twenty years since it has been remarkably resilient in spite of its age, but it is beginning to have problems especially due to the rapid growth in internet technology and the increase in networking devices is almost depleting its addressing space and outweighing its general functionalities especially in security of data. For this reason and the other reasons mentioned earlier in the paper, IPv6 was designed to address the limitations of the previous version, IP4. Ipv6, sometimes referred to as IP generation next (IP ng) was designed with the limitations and shortcomings of IPv4 in consideration. A number of problems in the previous version are fixed by the introduction of IPv6 such as the limited number of available IPv4 addresses since there is a growing shortage of IPv4 addresses, which are needed by all new machines added to the Internet. It also adds many improvements to IPv4 in areas such as routing and network auto-configuration. IPv6 is expected to gradually replace IPv4, with the two coexisting for a number of years during a transition period since most of the network still uses the previous version of the internet protocol and sudden transition is next to impossible since it will require complicated Software changes in all the networked devices which can be a daunting task. The main reason for IPv6 design is to address the shortage of addressing space experienced in IPv4. IPv6 has presents an addressing space too large that cater for feature networking devices since its depletion is next to impossible. The original design of IPv4 lacks certain functionalities that are involved with mobility, quality and security since it was designed many years ago. It therefore require additional protocols to enable it handle the functionalities since they are not integrated within the protocol itself. In addition to the addressing space problem and the missing functionalities, the growing number of elements in the routing table called for the development of a higher version of the internetworking protocol, IPv6. The IPv6’s main characteristics including lager addressing space, simplified routing, automatic configuration and improved security, were designed to aid in solving the problems that exist in the previous version, IPv4. References Li, Q., Jinmei, T., & Shima, K. (2007). IPv6 core protocols implementation. Amsterdam: Morgan Kaufmann. Koodli, R. S., & Perkins, C. E. (2007). Mobile inter-networking with IPv6 concepts, principles, and practices. Hoboken, N.J.: Wiley-Interscience. 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(2011). IPv6 for enterprise networks. Indianapolis: Cisco Press. Top of Form Bottom of Form Hari, S. (2010). Performance evaluation of multicast routing on IPv4 and IPv6 networks. New York: Wiley and sons. Asadullah, S. (2009). Deploying IPv6 in Broadband Access Networks. New York: Wiley and sons. Manepalli, S. (2009). Enhanced handoff algorithm for the co-existence of mobile IPV4 and IPV6 networks. New York: Wiley and sons. Top of Form Read More