   Hey, network admins... what do you think about broadcasts?
  Working on a P2P app at this moment, I''d like to know what network admins think about broadcasting and multicasting. From several sides I hear it''s a big nono from the admins point of view. From the other side, it''s the easiest to implement for a local network.So, what are your views on broadcasting and multicasting? 
  Broadcasting is fine as long as you aren''t an idiot with it and flood your local network. Any properly configured network shouldn''t leak packets to the outside or let unwanted broadcast packets in.IP Multicast is not widely supported unless you are connected to research networks such as MBone or Abilene due to implementation costs, lack of knowledgable staff and security concerns. Residential and small business users are out of luck. Because of this, a lot of research has been put into Application based Multicast (see NICE, Narada, ALMI). Basically, you build your own overlay network and use connected hosts instead of dedicated routers to direct your traffic. This is what most of the current p2p programs do. ;  My opinion is that multicast isn''t implemented not because of "lack of knowledgable staff" but because it''s a broken concept.Suppose a multicast set is set up between you and me. The routers between you and me know about this set. Now, Joe wants to join. To be able to join, Joe''s router needs to know about the set, too. This means that, for multicast join to work, EVERY ROUTER ON THE PLANET needs to know about EVERY MULTICAST SET.Unicast, where one IP broadcasts and multiple listeners can share circuits as far as they''ll go shared, is a good idea, and there''s a little bit of progress on that, but the progress has been slow, probably because bandwidth providers make more money by sending more bandwidth, and because the broken-ness of multicast has put people off the whole area. ;  It''s not much as what is the smartest tactic for using those techniques, it''s more like are they accepted by professional ICT centers? The application is meant to be commercially used in a professional environment by network administrators.If the implemented broadcasting/multicasting techniques witholds people from buying the application, I should look for alternatives.From a few sources I have heard that ICT professionals rather not have products that broadcasts/multicasts over their network because they have to change thingies in their routers, and makes switches as good as useless.I''d like to hear what other people think about this too.Now, this might not be exactly the right forum, but I thought I''d give it a shot anyway, as any opinion is better than no opinion. 