128 bits. The length of IPv6 is 128 bits.Internet Protocol version 6 (IPv6) is the latest IP revision, developed as a successor to IPv4.IPv6 provides a much larger address pool so that many more devices can be connected to the Internet.It ALSO IMPROVES ADDRESSING and routing of network traffic.The IPv6 anatomy graphic below represents just one possible configuration of an IPv6 address, although there are many different possibilities.A bit is a binary digit, the smallest increment of data on a computer. A bit can hold only one of two values: 0 or 1.Bits are usually assembled into a group of eight to form a byte.