I'm working on an implementation of a NB application for Hydrogen controller to controll switches according to the ARPPath protocol rules. I started using the Learning Switch example as my reference and with this I have developed the learning phase of the protocol. Now I have to approach the fixing paths phase, for which I need to detect link-down events. I have read that switches send to the controller messages called PortStatusMessages to notify this, but I'm not able to find the event to handle these kind of messages. I tried registering a new class as the listener of these events with the NotificationService (following how the LearningSwitch application do it), but it is not triggered when I bring down a link with mininet.
I hope someone can help me with the handler of this link-down event.
Thanks in advance.