Thanks, Brian. The first issue was an omission of #defines. IPv6 isn't a necessity for the UNP source, I believe.
The next issue I have is: mcast_leave.c: In function `mcast_leave_source_group': mcast_leave.c:78: error: storage size of 'mreq' isn't known 76: #ifdef IP_DROP_SOURCE_MEMBERSHIP 77: case AF_INET: { 78: struct ip_mreq_source mreq; Which I believe is telling me that struct ip_mreq_source isn't defined. Is this struct to do with IPv6 and how would I know that? When I google for ip_mreq_source, I'm led to believe that it's defined in net/udp.h (which I infer corrleates to usr/include/netinet/udp.h). Thanks, Huw -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/