IP Sec Fail Over

Hello

Can any one suggest me the best way for IP Sec WAN Fail over , I have two site with Cyberaom i had configured Mikrotik VPN IP Sec which talk properly wtih cyberoam, I want that if my one site cyberoam fail the IP sec should establish to other site cyberoam.

Please advice how can i configure the mikrotik IP Sec VPN Failover ??

Regards

NT