Hi, If you are talking about same different multicast groups but same port, you are out of luck on linux. There is a long debate on whether duplicated messages are expected. You can google it. Anyway, in short, you have to filter duplicates at the application level. ________________________________ From: Yuri T. <br0adcast.007@gmail.com> To: boost-users@lists.boost.org Sent: Wed, September 8, 2010 12:41:52 PM Subject: [Boost-users] asio multicast receiver takes all traffic addressed to the same port (example/multicast/receiver.cpp) Hi, In my network there are multiple multicast streams with different addresses, but with the same port. I tried to run an example from the asio library (example/multicast/receiver.cpp). In Windows it works fine but in linux if you run multiple copies of the application they receive all packets arriving on the specified port and ignore the broadcast address. How to filter packets by multicast address? (senderEndpoint contain real IP, not multicast)