Cisco Systems OL-8550-09 Understanding IPv6

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

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