S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
Extended IPv6 Address Space for Unique Addresses
IPv6 extends the address space by quadrupling the number of network address bits from 32 bits (in IPv4)
to 128 bits, which provides many more globally unique IP addresses. By being globally unique, IPv6
addresses enable global reachability and end-to-end security for networked devices, functionality that is
crucial to the applications and services that are driving the demand for more addresses.
IPv6 Address Formats
IPv6 addresses are represented as a series of 16-bit hexadecimal fields separated by colons (:) in the
format x:x:x:x:x:x:x:x. The following are examples of IPv6 addresses:
It is common for IPv6 addresses to contain successive hexadecimal fields of zeros. To make IPv6
addresses easier to use, two colons (::) may be used to compress successive hexadecimal fields of zeros
at the beginning, middle, or end of an IPv6 address (the colons represent successive hexadecimal fields
Two colons (::) can be used only once in an IPv6 address to represent the longest successive hexadecimal
fields of zeros.
The hexadecimal letters in IPv6 addresses are not case-sensitive.
IPv6 Address Type
Cisco MDS 9000 Family CLI Configuration Guide
IPv6 Address Formats, page 46-2
IPv6 Address Prefix Format, page 46-3
IPv6 Address Type: Unicast, page 46-3
IPv6 Address Type: Multicast, page 46-5
ICMP for IPv6, page 46-6
Path MTU Discovery for IPv6, page 46-7
IPv6 Neighbor Discovery, page 46-7
Router Discovery, page 46-9
IPv6 Stateless Autoconfiguration, page 46-9
Dual IPv4 and IPv6 Protocol Stacks, page 46-10
lists compressed IPv6 address formats.
Compressed IPv6 Address Formats
Configuring IPv6 for Gigabit Ethernet Interfaces
OL-16184-01, Cisco MDS SAN-OS Release 3.x