Hi list: Using MSVCPP C++ 9.0 and Boost_1_43_0, and trying to follow the examples in the tutorial. The Daytime.4 example hangs in line size_t len = socket.receive_from(boost::asio::buffer(recv_buf), sender_endpoint); it seem that wait indefinitely for a response. Using this server: char* serverName = "ntp-nist.ldsbc.edu"; // 198.60.73.8 LDSBC, Salt Lake City, Utah Neither with: char* serverName = "time-nw.nist.gov" or any other in the http://tf.nist.gov/tf-cgi/servers.cgi# list. By the way, the Daytime.1 (asynchronous TCP datytime client) example and Timer1 to 5 examples works fine for me. Any suggestion would be appreciated. Thanks A.J.Millan