Hello, in Stevens "UNIX Network Programming, Vol.1" I read that the socket API is defined by POSIX 1003.1g. Does this standard define also such stuff like datalink access and UDPCTL_CHECKSUM (UDPCTL_xxx constants) ? Is LINUX full P1003.1g complaint? Exists a document which summarizes the differences in networking stuff between LINUX and systems which are derived from BSD and SVR4? Thanks. with regards, Oliver - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org