IPv4 Mapped Address - 0:0:0:0:0:FFFF::/96

Like its predeccesor, IPv4 Mapped address is a transition technology to aid the deployment of IPv6 protocol.  It is used to enable IPv6 devices to communicate through IPv4 connected networks (see IPv4 Compatible Address for more explanation).

The format for IPv4 Mapped address has the first 80 bits set to zeros, followed by the next 16 bits set to all ones and finally, the last 32 bits written in dotted decimal appended to then end forming 128 bit IPv6 address as illustrated below.

  • 16 bits0
  • 16 bits0
  • 16 bits0
  • 16 bits0
  • 16 bits0
  • 16 bits0
  • 32 bitsIPv4 Address
  • 0
  • 0
  • 0
  • 0
  • 0
  • FFFF
  • 12.155.166.101


An example of an IPv4 Class A address of 12.155.166.101 would look like this in IPv4 Mapped address 0000:0000:0000:0000:0000:FFFF:12.155.166.101 or ::FFFF:12.155.166.101 in IPv6's short form.

Click on this link to examine this IPv4 Mapped address using the Advanced Online IPv6 Subnet Calculator: 0000:0000:0000:0000:0000:FFFF:12.155.166.101