HNA and heterogeneous nodes

In section 12.7, RFC3626 states that all nodes in a MANET does not need to implement HNA support for external access to work in a distributed manner. This is not true. Because of the hop by hop routing explained in the previous section, all nodes need to implement HNA functionality. In the scenario depicted in figure 13.1, if IN1 does not implement HNA support it will still forward HNA messages from GW1 to A due to the default forwarding algorithm. A will therefore still add a default route setting IN1 as the next-hop. All Internet-destined traffic from A will then be sent to IN1. However, since IN1 did not process the HNA info from GW1, it has not set up a default route. IN1 will therefore drop all Internet traffic received from A.