Hi, On WinXP, I successfully implemented an application that listens to multiple multicast groups (different IPs same port). When I recompiled that app on Linux, on another box, I started getting duplicate datagrams. After messing around for a long while, I got it working. I had to change two things: socket.bind was changed so that it no longer was given 'any' and the port, but the multicast address and port. socket.set_option was changed so that it no longer was given only the multicast address, but both the multicast address and local address. Moving this code back to Windows stops it working! I then stumbled across this while researching my issue: http://osdir.com/ml/lib.boost.asio.user/2007-04/msg00135.html I could not find this information anywhere in the documentation. Could someone point me in the right place? Does it also mean that the statement "Boost.Asio is a cross-platform C++ library for network and low-level I/O programming that provides developers with a consistent asynchronous model using a modern C++ approach." In the docs is inaccurate for multicast? If not, is there a cross-platform, asio way? Cheers, Birju Schneider Trading 4th Floor, 25 Copthall Avenue London EC2R 7BP -------------------------------------------------------- Message from: Birju.Prajapati@schneidertrading.com Message to: boost-users@lists.boost.org Attached files: 0 This e-mail and any files transmitted with it are confidential, may be legally privileged, and are for the sole use of the intended recipient. Copyright in this e-mail and any accompanying document created by us is owned by us. If you are not the intended recipient of this e-mail or any part of it please telephone our IT Department at the number shown above or by e-mail at info@schneidertrading.com. You should not use or disclose to any other person the contents of this e-mail or its attachments (if any), nor take copies. This e-mail is not a representation or warranty and is not intended nor should it be taken to create any legal relations, contractual or otherwise. Schneider Trading Associates Ltd (Registration No. 3692131) is incorporated in England and Wales and the registered office is at 25 Copthall Avenue, London EC2R 7BP. The company is authorised and regulated by the Financial Services Authority