Extended Ipv6 Address Space For Unique Addresses; Ipv6 Address Formats; C H A P T E R 8 Configuring Ipv6 For Gigabit Ethernet Interfaces - Cisco MDS 9000 series Configuration Manual

About IPv6
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
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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
of zeros).
Two colons (::) can be used only once in an IPv6 address to represent the longest successive hexadecimal
Note
fields of zeros.
The hexadecimal letters in IPv6 addresses are not case-sensitive.
Note
Table 8-1
IPv6 Address Type
Unicast
Multicast
Cisco MDS 9000 Family NX-OS IP Services Configuration Guide
8-9
IPv6 Address Formats, page 8-9
IPv6 Address Prefix Format, page 8-10
IPv6 Address Type: Unicast, page 8-10
IPv6 Address Type: Multicast, page 8-12
ICMP for IPv6, page 8-13
Path MTU Discovery for IPv6, page 8-14
IPv6 Neighbor Discovery, page 8-14
Router Discovery, page 8-16
IPv6 Stateless Autoconfiguration, page 8-16
Dual IPv4 and IPv6 Protocol Stacks, page 8-17
2001:0DB8:7654:3210:FEDC:BA98:7654:3210
2001:0DB8:0:0:8:800:200C:417A
Table 8-1 lists compressed IPv6 address formats.
Compressed IPv6 Address Formats
Uncompressed Format
2001:0DB8:800:200C:0:0:0:417A 2001:0DB8:800:200C::417A
FF01:0:0:0:0:0:0:101
Chapter 8 Configuring IPv6 for Gigabit Ethernet Interfaces
Compressed Format
FF01::101
OL-19525-01,Cisco MDS NX-OS Release 4.2(1)