Cisco Systems 3750E manual IPv6 Addresses, 39-2

Chapter 39 Configuring IPv6 Unicast Routing

Understanding IPv6

The architecture of IPv6 allows existing IPv4 users to transition easily to IPv6, and provides services such as end-to-end security, quality of service (QoS), and globally unique addresses. The flexibility of the IPv6 address space reduces the need for private addresses and the use of Network Address Translation (NAT) processing by border routers at the edge of networks. IPv6 provides newer unicast methods, introduces hexadecimal values into the IP address, and uses colons (:) instead of periods (.) as delimiters.

IPv6 also provides these advantages over IPv4:

•Easier address management and delegation

•Easy address autoconfiguration with stateless autoconfiguration, which is similar to DHCP but does not require a specified DHCP application or server

•Embedded IPsec (encrypted security)

•Routing optimized for mobile devices

•Duplicate Address Detection (DAD) feature

For information about how Cisco Systems implements IPv6, go to this URL:

http://www.cisco.com//warp/public/732/Tech/ipv6/

This section describes IPv6 implementation on the switch. These sections are included:

•IPv6 Addresses, page 39-2

•Supported IPv6 Unicast Routing Features, page 39-3

•Unsupported IPv6 Unicast Routing Features, page 39-6

•Limitations, page 39-7

•IPv6 and Switch Stacks, page 39-7

•SDM Templates, page 39-9

IPv6 Addresses

IPv6 supports three types of addresses: unicast (one-to-one), multicast (one-to-many), and anycast (one-to-nearest). Multicast addresses replace the use of broadcast addresses. The switch supports only IPv6 unicast addresses. The switch does not support site-local unicast addresses, anycast addresses, or multicast addresses in this release.

The IPv6 128-bit addresses are represented as a series of eight 16-bit hexadecimal fields separated by colons in the format: x:x:x:x:x:x:x:x. 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

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

39-2 OL-9775-02