I have my company network consists of 4 sites. Each one connected to other by Mugs.(Serail - 45 Mbps). In each site the main router in connected to other router which in connected to Firewall & then L3 Switch then L2 Switch & then Servers & Users.
Between 2 sites there is VPN Connection also. I have implement OSPF on this VPN network. Now there is static route.
So how can I implement OSPF?
You may need to configure GRE over IPSec Tunnel instead of the site-to-site VPN connection.
GRE over IPsec will forward the multicast packets that OSPF needs to build up neighbor relationship and send - receive updates.
Here's a link that can be useful for you describing how to configure GRE over IPSec with OSPF: