29-03-2011 1 KAMRAN Roll no. 29 Mcs-II Batch-IV
2 Overview1. IPv4 and IPv62. Difference b/w IPv4 and IPv63. Deficiencies of IPv44. Advantages od IPv65. Transition from IPv4 to IPv6
3 1. IPv4 and IPv6IPv4: a mechanism used by TCP/IP still using today both are connectionless servicesIPv6: * newer version. * deployed in 1999. * for future use.
4 2. Difference b/w IPv4 and IPv6S.no IPv4 IPv61.Address size 32-bit 128-bit2.Address format Dotted decimal notation Hexadecimal notation 184.108.40.206 3FFE:F200:AB00:0123: 0234:890A:XC01:SD98:3.Prefix notation 220.127.116.11/24 3FFE:F200:AB00:0123::/48 32 1284.No. of Addresses 2 = 4 billions + 2 =340,282,366,920, 938,463,374,607, 431,768,211,456 haeder data area5.datagram format 1.................N base extension payload area header header6. Headers IPv4 has a 20 octets i.e. IPv6 has 8 fields with a 160 bits, containig info. total size of 40 octets i.e. essential to routing and 320 bits. delivery. it consists of 12 fields
7. Datagram formats: header dataVER 4 bits HLN 4 bits service type total length 16 bits 8 bits Identification 16 bits flags 3 bits fragmentation offset 13 bitstime to live 8 bits protocol 8 bits header checksum 16 bits Source IP address Destination IP address Options 32-bits Address WHILE
Format of an IPv6 datagramVER PRI Flow label Payload length Next header Hop limit Source address Destination addressnext header header length next header header lengthnext header header length
NOW TO COMPARE THE HEADER FORMATS1. " Header length" is eliminated from IPv6 b/c length is fixed in IPv62. "Source type" field is also eliminated . The "priority & flow label" aretogether over the service field in IPv6.3. The "total length" field is eliminated in IPv6 & replaced by "Payloadlength".4. the "Identification, flags, & offset" field are eliminated too. they areincluded in the "fragmentation extension header".5. the "protocol" field is replaced by "Next header" field.6. "time to live" field are called hop limit in IPv6.7. The "header checksum" is removed because the checksum areprovided by upper layers & is no need here.8. the "option" field are implemented as "Extention header" in IPv6.
3. Deficiencies of IPv41. subnetting, classless addressing and NAT address depliction is still long term problems2. The Internet must accummodate real-time audio, video tx. this typeof tx requires minimum delay strategies and reservation for resourses.3. The Internet must accummodate encryption and authentication ofdata.but this is not provided in IPv4. NOW 4. Advantages od IPv61. larger address space (which has a huge increase in address space)2. better header format (in which options are separated from baseheader) this simplifies speed up the routing process.3. new options (to allow for additional functionality)4. Support for high security
5. Transition from IPv4 to IPv6 three strategiesDual stack Tunneling Header translation
dual stack transport & app. layers IPv4 IPv6 underlying LAN or WAN technologyto IPv4 system to IPv6 system
SOME QUESTIONS1.What is the main reason for switching fro IPv4 to IPv6 ?Ans: IP address storage.2. Identify any two differences b/w the IPv4 & IPv6 header format ?Ans: 1. IPv6 use 360 bit while IPv4 uses 160 bits 2. IPv6 has 8 fields while IPv4 has 12 fields. 3. Explain the concept of tunneling ?Ans: tunneling is a strategy used when two computers using IPv6 want to communicate, the packet must pass through some region that uses IPv4. now to pass through this region, the IPv6 packet is encapsulated in an IPv4 packed and then it leaves its capsule when it exit the region of IPv4.it seems that it goes through a tunnel. 4. Name two main aspects in Internet security ? Ans: 1. Authentication Header 2. Encapsulating Security Payload (ESP) Header