Thanks for your response, I think I encountered one of the "slow" machines today while I was running some tests. I guess there are just some slow ones in every group. I met with some network analysts from my university today and they explained how since the network is operating on a mixed CGMP/IGMPv2 environment multicasts are sometimes flaky. So, now that I may have found a source of the problem my question is if any has any experience using udpcast in a mixed environment, and if so what steps they took to make udpcast more reliable. And also if there is a version of udpcast that uses IGMPv2 rather than IGMPv3. Thank you, Mike _______________________________________________ Udpcast mailing list Udpcast(a)udpcast.linux.lu https://lll.lgl.lu/mailman/listinfo/udpcast