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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
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Chapter 1 Configuring IPv6 Unicast Routing
Understanding IPv6
Dual IPv4 and IPv6 Protocol Stacks
You must use the dual IPv4 and IPv6 template to allocate hardware memory usage to both IPv4 and IPv6
protocols.
Figure 1-1 shows a router forwarding both IPv4 and IPv6 traffic through the same interface, based on
the IP packet and destination addresses.
Figure 1-1 Dual IPv4 and IPv6 Support on an Interface
Use the dual IPv4 and IPv6 switch database management (SDM) template to enable IPv6 routing dual
stack environments (supporting both IPv4 and IPv6). For more information about the dual IPv4 and IPv6
SDM template, see Chapter 1, “Configuring SDM Templates.”
The dual IPv4 and IPv6 templates allow the switch to be used in dual stack environments.
• If you try to configure IPv6 without first selecting a dual IPv4 and IPv6 template, a warning message
appears.
• In IPv4-only environments, the switch routes IPv4 packets and applies IPv4 QoS and ACLs in
hardware. IPv6 packets are not supported.
• In dual IPv4 and IPv6 environments, the switch routes both IPv4 and IPv6 packets and applies IPv4
QoS in hardware.
• The switch supports QoS for both IPv4and IPv6 traffic.
• If you do not plan to use IPv6, do not use the dual stack template because this template results in
less hardware memory capacity for each resource.
For more information about IPv4 and IPv6 protocol stacks, see the “Implementing IPv6 Addressing and
Basic Connectivity” chapter of Cisco IOS IPv6 Configuration Library on Cisco.com.
DHCP for IPv6 Address Assignment
DHCPv6 enables DHCP servers to pass configuration parameters, such as IPv6 network addresses, to
IPv6 clients. The address assignment feature manages non-duplicate address assignment in the correct
prefix based on the network where the host is connected. Assigned addresses can be from one or multiple
prefix pools. Additional options, such as default domain and DNS name-server address, can be passed
back to the client. Address pools can be assigned for use on a specific interface, on multiple interfaces,
or the server can automatically find the appropriate pool.
Beginning with Cisco IOS Release 12.2(58)SE, the switch supports these features:
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3ffe:yyyy::1
10.1.1.1
IPv6
IPv4