In an active/active configuration in takeover mode, the surviving controller interfaces will reflect the identity...

In takeover mode, this network interface assumes the identity of the network interface on the partner

http://www.wafl.co.uk/tag/ifconfig/#sthash.3rsjaDZD.dpuf

For the partner interface configuration to be persistent across reboots, you must include the ifconfig command in the /etc/rc file

http://hd.kvsconsulting.us/netappdoc/801docs/html/ontap/nag/GUID-525FCF4E-109D-4E6F-9256-C6E56438CA9A.html