Created attachment 180593 [details]
sketch of a patch fixing the issue
ng_cisco's cisco_notify() routine only sends flow control messages to nodes connected via 'inet' hook, completely ignoring those connected via 'inet6'. This poses some problem if peer node relies on link status information passed from ng_cisco. I'd therefore like to suggest a patch (perhaps something similar to what I attached). All it does is to make ng_cisco node pass flow control messages to *both* 'inet' and 'inet6' peers. It seems to me that it is both possible and sensible to expect both mentioned hooks to be connected at the same time.