Docker image cannot reach outside network

Hello All,

I am extremely new to docker world. I have been task upon to setup an application on docker image. For the task a predefined VM ova is deployed and inside the vm docker environment is pre setup. The deployment requires docker image to reach outside world. But in the setup I am unable to reach the outside network. The connection reaches to my external physical interface but the physical interface doesn’t forward the reply to the docker image.

When I try to ping from inside image I can not reach outside network.

But when I ping the directly connected physical interface of the machine I can ping it from the docker image.

Upon performing tcpdump in docker interface(docker0) I can see that the ping request is going outside but not a single response received.

If I ran tcpdump on the main interface(eth0) I can see that the packet is being forwarded to the internet and response is being received but that response is not being forwarded to docker container.

The ip forward is set to true.

The above are the default iptables rules set on the machine.

Docker version 20.10.17-ce, build a89b84221c85

I will be very grateful for any response.