Hi, I have a function(in the kernel, ip_rcv_finish... before the ip forwarding code.) that takes in packets, replaces the dest. ip:port, and sends to that machine. (ip forwarding is enabled.) I need to recalculate the checksum..... ip checksumming works fine(ip_fast_csum)... but, the tcp checksum is shown as incorrect on ethereal. The packets are not delivered to the new dest.... Also, what is the skb->csum, in case there is no data (e.g. for ACK or FIN -only packets)? TIA, --- - Amit http://amitshah.nav.to/ amitshah@gmx.net -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ IRC Channel: irc.openprojects.net / #kernelnewbies Web Page: http://www.kernelnewbies.org/