Ipfs private network is support nat traversal ?

I deployed a private network with ipfs. Three of the nodes have public ip addresses. And the three of them act as boot nodes. Their names are A,\B\C. There are also two nodes that do not have public ip addresses. They’re behind two different routers. Now we call them D and E nodes. D nodes can only be connected to A\B\C, and E nodes can only be connected to A\B\C. Node D cannot be connected to node E.