About the IPv6 Address Format

This topic explains the format for IP version 6 (IPv6) addresses, including how to compress them, and it gives some examples.

All IPv6 addresses are 128 bits long, written as 8 sections of 16 bits each. They are expressed in hexadecimal representation, so the sections range from 0 to FFFF. Sections are delimited by colons, and leading zeroes in each section may be omitted. If two or more consecutive sections have all zeroes, they can be collapsed to a double colon.

• IPv6 addresses have the following format in which each xxxx is a 16-bit hexadecimal value, and each x is a 4-bit hexadecimal value.

  xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx

• Here is an example of an IPv6 address:

  3FFE:0000:0000:0001:0200:F8FF:FE75:50DF

• For an IPv6 address that contains consecutive fields of leading zeros, you can omit the zeros from each section. If you take this approach, you can write the example address in the following way:

  3FFE:0:0:1:200:F8FF:FE75:50DF

• For an IPv6 address that includes contiguous sections each of which contain zeros, you can compress the 16-bit groups of zeros to double colons (::) but you can use the double-colon delimiter only once within a single IPv6 address, as shown in the following example:

  3FFE::1:200:F8FF:FE75:50DF

Related Topics

• About the IPv6 Address Space, Addressing, and Address Types
• About IPv6 Address Types and How Junos OS for SRX Series Services Gateway and J-series Devices Use Them
• About the IPv6 Basic Packet Header
• Understanding IPv6 Packet Header Extensions
• Understanding IP Version 6 (IPv6)