本文简要说明ipv6 header

IPV6 Header格式 链接到标题

下面分别是ipv6和ipv4 header header 图1.1 IPV6 Header

IPV6 Header共40byte

  • Version 4-bit Internet Protocol version number = 6.
  • Traffic Class 8-bit traffic class field
  • Flow Label 20-bit flow label
  • Payload Length 16-bit unsigned integer,Length of the IPv6 payload, i.e., the rest of the packet following this IPv6 header, in octets
  • Next Header 8-bit selector. Identifies the type of header immediately following the IPv6 header
  • Hop Limit 8-bit unsigned integer. Decremented by 1 by each node that forwards the packet. The packet is discarded if Hop Limit is decremented to zero.
  • Source Address 128-bit address of the originator of the packet
  • Destination Address 128-bit address of the intended recipient of the packet

IPV6与IPV4 Header的差别 链接到标题

v4header 图1.2 IPV4 Header

1.移除6个栏位 链接到标题

header length(IHL) Type of Service Identification Flags Fragment Offset Header Checksum

2.重命名3个栏位 链接到标题

Total Length(Payload Length) Time to Live(Hop Limit) Protocol

3.选项机制重定义 链接到标题

Source Routing Route Recording

4.新增两个栏位 链接到标题

Traffic Class(Priority) Flow Label

5.V6主要简化 链接到标题

  • 所有header格式固定(40byte)
  • 移除了checksum
  • 移除了router封包切割机制

IPV6选项机制 链接到标题

IPV4的选项机制导致了Header长度变化，IPV6定义了扩展Header来解决该问题。

1. IPV6扩展Header类型 链接到标题

  • Hop-by-Hop Options header
  • Destination Options header
  • Routing header
  • Fragment header
  • Authentication header
  • Encapsulating Security Payload header
  • Destination Options header
  • upper-layer header

2. 扩展Header使用方式 链接到标题

由IPV6 Header+ex-header’s+Data组成 ex-header

3. 扩展header示例 链接到标题

路由header routeh

fragment header fragh

fragement 扩展header fraghe

参考 链接到标题

以上图片部分取至台湾清华大学黄能富教授《物联网概论》课件