IPsec Ikev2 Tunnel Not Working

I am trying to setup IPsec VPN client on my OpenWRT Router. I have used strongswan package for this. I have configured the VPN client and the router connects to the VPN successfully. But the only problem is I am not able to forward the traffic of the VPN to the devices which are connected to the Router. When I do ifconfig -a I get this interface which is the tunnel for the IPsec traffic and it shows only RX traffic.

ip_vti0   Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  
          UP RUNNING NOARP  MTU:1480  Metric:1
          RX packets:2337 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1 
          RX bytes:246475 (240.6 KiB)  TX bytes:0 (0.0 B)

Here is the link to all my configuration : IPsec Client Not Working