Where is the debugger for my software-defined network?

Nikhil Handigol, Brandon Heller, Vimalkumar Jeyakumar, David Mazières, Nick McKeown. Where is the debugger for my software-defined network?. In Nick Feamster, Jennifer Rexford, editors, Proceedings of the first workshop on Hot topics in software defined networks, HotSDN@SIGCOMM 2012, Helsinki, Finland, August 13, 2012. pages 55-60, ACM, 2012. [doi]

@inproceedings{HandigolHJMM12,
  title = {Where is the debugger for my software-defined network?},
  author = {Nikhil Handigol and Brandon Heller and Vimalkumar Jeyakumar and David Mazières and Nick McKeown},
  year = {2012},
  doi = {10.1145/2342441.2342453},
  url = {http://doi.acm.org/10.1145/2342441.2342453},
  researchr = {https://researchr.org/publication/HandigolHJMM12},
  cites = {0},
  citedby = {0},
  pages = {55-60},
  booktitle = {Proceedings of the first workshop on Hot topics in software defined networks, HotSDN@SIGCOMM 2012, Helsinki, Finland, August 13, 2012},
  editor = {Nick Feamster and Jennifer Rexford},
  publisher = {ACM},
  isbn = {978-1-4503-1477-0},
}