Hello, > ntpd needs to send responses back using the same IP address that it > received the original request on. To track the addresses, it uses > separate file descriptors. setsockopt IP_PKTINFO,IPV6_PKTINFO + sendmsg/recvmsg + controlmsg is better way to do this, you need only single FD. Regards, -- Jan Oravec XS26 coordinator 6COM s.r.o. 'Access to IPv6' http://www.6com.sk http://www.xs26.net