A transition mechanism enables IPv6 hosts and routers to be compatible with IPv4 hosts and routers. Starting with Data ONTAP 7.3.1, a dual stack mechanism is used for transitioning from IPv4 to IPv6.
In the dual stack mechanism, the following modes are supported:
- Only IPv4 mode: In this mode, IPv6 is not enabled.
- Only IPv6 mode: In this mode, IPv6 is enabled and IPv4 addresses are not configured on any interface.
- IPv6/IPv4 mode: In this mode, IPv6 is enabled and both IPv4 and IPv6 addresses are configured on the network interfaces.
Attention: In the "Only IPv6 mode," address lookup can return both IPv4 and IPv6 addresses. If you use an IPv4 address to set up communication in the "Only IPv6 mode," the communication fails. Therefore, you should have at least one IPv4 address configured in a network interface and then use the "IPv6/IPv4 mode."
Data ONTAP does not support the following IPv6 transition mechanisms (defined in RFC 2893):
- Configured tunneling of IPv6 over IPv4
- IPv4-mapped IPv6 addresses
- Automatic tunneling of IPv6 over IPv4