Thanks for the support.
I thought all ports are open from the firewall in the network side (Oracle VM bridge firewall), but only TCP ports were opened. So no UDP packets were transmitted between nodes even if all firewalls in the nodes are disabled.
When the VM bridge firewall was configured to allow UDP ports it started working. The netcat is really good to check UDP and also tshark. I checked the packets upto node eth level with - tshark -V –i eth0 –d udp.port=8472,vxlan –f “port 8472” (works for Fannel / cannel)