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Ipv6_final

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KartiKeya Thorat
KartiKeya Thorat

This document provides an overview of IPv6 including problems with IPv4, features of IPv6, and how IPv6 addresses some of IPv4's limitations. It discusses that IPv4 addresses will exhaust in the next 5 years and lacks features like quality of service support, security, and mobility. IPv6 supports a longer 128-bit address, simplified header format, auto-configuration, security, and quality of service capabilities through flow labeling. Key aspects of IPv6 include longer addresses, stateless auto-configuration, and extension headers to allow for optional features.

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Presented by Anuraj Sonawane & Kartik thorat
Problems with IPv4 Basic IPv6 Protocol IPv6 features 2
IPv4 has 32 bit addresses. Flat addressing (only netid + hostid with fixed boundaries) Results in inefficient use of address space. Class B addresses are almost over. Addresses will exhaust in the next 5 years. IPv4 is victim of its own success. 3
Maximum header length is 60 octets. (Restricts options) Maximum packet length is 64K octets. (Do we need more than that ?) ID for fragments is 16 bits. Repeats every 65537th packet. (Will two packets in the network have same ID?) Variable size header. (Slower processing at routers.) No ordering of options. (All routers need to look at all options.) 4
Lack of quality-of-service support. Only an 8-bit ToS field, which is hardly used. Problem for multimedia services. No support for security at IP layer. Mobility support is limited. 5
Strict monitoring of IP address assignment Private IP addresses for intranets Only class C or a part of class C to an organization Encourage use of proxy services Application level proxies Network Address Translation (NAT) Remaining class A addresses may use CIDR Reserved addresses may be assigned But these will only postpone address exhaustion. They do not address problems like QoS, mobility, security. 6
Header format simplification Expanded routing and addressing capabilities Improved support for extensions and options Flow labeling (for QoS) capability Auto-configuration and Neighbour discovery Authentication and privacy capabilities Simple transition from IPv4 7
Longer address - 32 bits 128 bits Fragmentation field moved to separate header Header checksum removed Header length removed (fixed length header) Length field excludes IPv6 header Time to live Hop limit Protocol Next header 64-bit field alignment TOS replaced by flow label, traffic class 8
128-bit addresses Multiple addresses can be assigned to an interface Provider-based hierarchy to be used in the beginning Addresses should have 64-bit interface IDs in EUI- 64 format Following special addresses are defined : IPv4-mapped IPv4-compatible link-local site-local 9
10 V ersion Traffic Class Flow Label Payload Lengtht Next Header Hop Limit SourceAddr (4 words) DestinationAddr (4 words) Options (variable number) 0 4 8 16 24 31 Data
Less used functions moved to extension headers. Only present when needed. Processed only by node identified in IPv6 destination field. => much lower overhead than IPv4 options Exception: Hop-by-Hop option header Eliminated IPv4s 40-byte limit on options Currently defined extension headers: Hop-by-hop, Routing, Fragment, Authentication, Privacy, End-to-end. Order of extension headers in a packet is defined. Headers are aligned on 8-byte boundaries. 11
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Ipv6_final

  • 2. Problems with IPv4 Basic IPv6 Protocol IPv6 features 2
  • 3. IPv4 has 32 bit addresses. Flat addressing (only netid + hostid with fixed boundaries) Results in inefficient use of address space. Class B addresses are almost over. Addresses will exhaust in the next 5 years. IPv4 is victim of its own success. 3
  • 4. Maximum header length is 60 octets. (Restricts options) Maximum packet length is 64K octets. (Do we need more than that ?) ID for fragments is 16 bits. Repeats every 65537th packet. (Will two packets in the network have same ID?) Variable size header. (Slower processing at routers.) No ordering of options. (All routers need to look at all options.) 4
  • 5. Lack of quality-of-service support. Only an 8-bit ToS field, which is hardly used. Problem for multimedia services. No support for security at IP layer. Mobility support is limited. 5
  • 6. Strict monitoring of IP address assignment Private IP addresses for intranets Only class C or a part of class C to an organization Encourage use of proxy services Application level proxies Network Address Translation (NAT) Remaining class A addresses may use CIDR Reserved addresses may be assigned But these will only postpone address exhaustion. They do not address problems like QoS, mobility, security. 6
  • 7. Header format simplification Expanded routing and addressing capabilities Improved support for extensions and options Flow labeling (for QoS) capability Auto-configuration and Neighbour discovery Authentication and privacy capabilities Simple transition from IPv4 7
  • 8. Longer address - 32 bits 128 bits Fragmentation field moved to separate header Header checksum removed Header length removed (fixed length header) Length field excludes IPv6 header Time to live Hop limit Protocol Next header 64-bit field alignment TOS replaced by flow label, traffic class 8
  • 9. 128-bit addresses Multiple addresses can be assigned to an interface Provider-based hierarchy to be used in the beginning Addresses should have 64-bit interface IDs in EUI- 64 format Following special addresses are defined : IPv4-mapped IPv4-compatible link-local site-local 9
  • 10. 10 V ersion Traffic Class Flow Label Payload Lengtht Next Header Hop Limit SourceAddr (4 words) DestinationAddr (4 words) Options (variable number) 0 4 8 16 24 31 Data
  • 11. Less used functions moved to extension headers. Only present when needed. Processed only by node identified in IPv6 destination field. => much lower overhead than IPv4 options Exception: Hop-by-Hop option header Eliminated IPv4s 40-byte limit on options Currently defined extension headers: Hop-by-hop, Routing, Fragment, Authentication, Privacy, End-to-end. Order of extension headers in a packet is defined. Headers are aligned on 8-byte boundaries. 11