When Nigel said that the pod network is flat, I was slightly confused as in a flat network, packets are sent to all devices connected to it. But that cannot be the case here,right?
A flat network usually refers to a network where there are no other devices the may interrupt the communication. These devices can be routers firewalls etc. So in a flat network different devices/pods should be able to talk to each other with no work involved such as creating routes or opening ports, etc.