Dear All I have written a client server program for file transmission from one system to other using UDP. Can i use the cksum number in the udp header to validate if the received packet is corrupted or not? If yes, how can i extract the header and validate it.. Also is there any way that i can call cksum in c program? Except popen("cksum","r") Any inputs will be of great help Thanks in advance Collins

Does this help: http://www.netfor2.com/udpsum.htm Have you tried the advice you got here: http://www.unix.com/high-level-programming/77778-udp-file-transfer-validation-checksum.html