ospf and openvpn

Hi,
Can someone can suggest me how to set up openvpn and ospfd from zebra to
enable ospf protocol to work over vpn link?
My topology is that i've one central point with two ISP connections an a
number of client sites which connects two openvpn deamons which listens
on two public IPs on central point.
I've managed to get connectivity using tun interface but i get
Packet from [10.8.0.11] received on link tun3 but no ospf_interface
in ospfd log.
I tried to set up the network using tap interfaces, well it worked but
I've got the situation when the route to one of the sites was routed via
loadbalanced all others sites.

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Regards
Dariusz Malec