39-2
Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter39 Configuring IPv6 Unicast Routing
Understanding IPv6
Understanding IPv6
IPv4 users can move to IPv6 and receive services such as end-to-end security, quality of service (QoS),
and globally unique addresses. The IPv6 address space reduces the need for private addresses and
Network Address Translation (NAT) processing by border routers at network edges.
For information about how Cisco Systems implements IPv6, go to:
http://www.cisco.com/en/US/products/ps6553/products_ios_technology_home.html
For information about IPv6 and other features in this chapter
See the Cisco IOS IPv6 Configuration Library:
http://www.cisco.com/en/US/docs/ios/12_2t/ipv6/ipv6_vgf.html
Use the Search field to locate the Cisco IOS software documentation. For example, if you want
information about static routes, you can enter Implementing Static Routes for IPv6 in the search field
to get this document about static routes:
http://www.cisco.com/en/US/docs/ios/ipv6/configuration/guide/ip6-stat_routes_ps6441_TSD_Pro
ducts_Configuration_Guide_Chapter.html
This section describes IPv6 implementation on the switch.
IPv6 Addresses, page 39-2
Supported IPv6 Unicast Routing Features, page39-3
Unsupported IPv6 Unicast Routing Features, page39-8
Limitations, page 39-9
IPv6 and Switch Stacks, page 39-9

IPv6 Addresses

The switch supports only IPv6 unicast addresses. It does not support site-local unicast addresses, anycast
addresses, or multicast addresses.
The IPv6 128-bit addresses are represented as a series of eight 16-bit hexadecimal fields separated by
colons in the format: n:n:n:n:n:n:n:n. This is an example of an IPv6 address:
2031:0000:130F:0000:0000:09C0:080F:130B
For easier implementation, leading zeros in each field are optional. This is the same address without
leading zeros:
2031:0:130F:0:0:9C0:80F:130B
You can also use two colons (::) to represent successive hexadecimal fields of zeros, but you can use this
short version only once in each address:
2031:0:130F::09C0:080F:130B
For more information about IPv6 address formats, address types, and the IPv6 packet header, see the
“Implementing IPv6 Addressing and Basic Connectivity” chapter of Cisco IOS IPv6 Configuration
Library on Cisco.com.
In the “Implementing Addressing and Basic Connectivity” chapter, these sections apply to the
Catalyst 3750switch:
IPv6 Address Formats
IPv6 Address Type: Unicast