Describes essential concepts and principles for using IPv6 as the primary address family in dual stack setups, covering deployment scenarios and network impacts.
A dual stack environment is a network that supports both IPv4 and IPv6 addressing, and where both can be used simultaneously. In a dual stack Cisco Catalyst SD-WAN environment, you can select a preferred address family, either IPv4 or IPv6, for establishing control and data connections.
Control connections
You can select a preferred address family, IPv4 or IPv6, to establish control and data connections in a dual stack network environment. Use the Dual Stack IPv6 Default drop-down list in Cisco SD-WAN Manager to set IPv6 or IPv4.
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Dual Stack IPv6 Default: True:
The device establishes IPv6 control connections with SD-WAN Manager and the SD-WAN Controller that the device is connected to.
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Dual Stack IPv6 Default: False:
The device establishes IPv4 control connections with SD-WAN Manager and the SD-WAN Controller that the device is connected to.
Data connections
Data connections or Bidirectional Forwarding Detection (BFD) sessions are established based on the IPv6 option set in local, remote devices. In a dual stack network environment, if you choose True for a local or remote device, the BFD session is an IPv6 connection. Otherwise, it is IPv4.
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Dual Stack IPv6 Default: True:
Establishes IPv6 BFD sessions.
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Dual Stack IPv6 Default: False:
Establishes IPv4 BFD sessions.
SD-WAN Validator
The Dual Stack IPv6 Default drop-down list options applies to devices, SD-WAN Manager, and SD-WAN Controller, but not to SD-WAN Validator.
The connections from SD-WAN Manager, SD-WAN Controller, and devices to the SD-WAN Validator are always dual (IPv4 and IPv6) in a dual stack network environment, regardless of the Dual Stack IPv6 Default setting.
NAT44 and NAT66
You can configure an IPv6 connection on devices that are at sites behind NAT44 and NAT66.
Benefits of setting IPv6 as the preferred address family
You have the option to migrate from IPv4 to IPv6, which allows you to have more IP addresses compared to IPv4. With IPv6, there can be no depletion of IP addresses.