I created a custom topology in mininet and added flows rules to the switches. I can ping the hosts but cannot see the topology on DLUX. I tried with other topology such as single and linear, these work fine. I do not understand what is the problem with the custom topology. If someone could shed some light.
It's strange that I can ping all of a sudden now without making any changes. I have faced this problem earlier too, where the controller doesn't work for a week or so and then starts running suddenly.