48-2
Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 48 Support for IPv6
About IPv6
For information about how Cisco Systems implements IPv6, go to this URL:
http://www.cisco.com/en/US/products/ps6553/products_ios_technology_home.html
This section describes the features that are supported for IPv6:
IPv6 Addressing and Basic Connectivity, page 48-2
DHCP, page 48-3
Security, page 48-3
QoS, page 48-3
Management, page 48-4
Multicast, page 48-4
Static Routes, page 48-5
First-Hop Redundancy Protocols, page 48-5
Unicast Routing, page 48-5
Tunneling, page 48-7
IPv6 Addressing and Basic Connectivity
The switch supports only IPv6 unicast addresses. It does not support site-local unicast 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. it is an example of an IPv6 address:
2031:0000:130F:0000:0000:09C0:080F:130B
The leading zeros in each field are optional, implementation is easier without them. it 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
The switch supports the following features:
IPv6 address types: Anycast
IPv6 default router preferences
IPv6 MTU path discovery
Neighbor discovery duplicate address detection
Cisco Discovery Protocol — IPv6 address family support for neighbor information
ICMPv6 redirect
ICMP rate limiting
DNS lookups over an IPv6 transport
uRPF
ICMPv6
AAAA DNS lookups over an IPv4 transport