IPv4 和 IPv6 是互联网协议版本 4 和互联网协议版本 6，IP 版本 6 是互联网协议的新版本，在复杂性和效率方面比 IP 版本 4 好得多。
IPv4 和 IPv6 的区别：
| IPv4 | IPv6 |
|---|---|
| IPv4 has 32-bit address length | IPv6 has 128-bit address length |
| It Supports Manual and DHCP address configuration | It supports Auto and renumbering address configuration |
| In IPv4 end to end connection integrity is Unachievable | In IPv6 end to end connection integrity is Achievable |
| It can generate 4.29×109 address space | Address space of IPv6 is quite large it can produce 3.4×1038 address space |
| Security feature is dependent on application | IPSEC is inbuilt security feature in the IPv6 protocol |
| Address representation of IPv4 is in decimal | Address Representation of IPv6 is in hexadecimal |
| Fragmentation performed by Sender and forwarding routers | In IPv6 fragmentation performed only by sender |
| In IPv4 Packet flow identification is not available | In IPv6 packetflow identification are Available and uses flow label field in the header |
| In IPv4 checksumfield is available | In IPv6 checksumfield is not available |
| It has broadcast Message Transmission Scheme | In IPv6 multicast and any cast message transmission scheme is available |
| In IPv4 Encryption and Authentication facility not provided | In IPv6 Encryption and Authentication are provided |
| IPv4 has header of 20-60 bytes. | IPv6 has header of 40 bytes fixed |