Hi Dieter,
1. Set virtual IP with following command in primary site:
ip addr add 192.168.1.10/24 dev eth0
/sbin/arping -A -I eth0 192.168.1.10 -c 5
2. Move virtual IP during takeover, you can adjust the scripts mentioned in HANA System Replication - Take-over process. You can also use cluster software to automatically move the virtual IP (which enables automatically take over)
Regards,
Ning Tong