Hello, I have some questions... 1)When data is copied to ICMP/UDP packets? when i trace kernel code in 2.4.26 kernel version is that in case of ICMP and UDP packets the packet gets its space allocated in ip_build_xmit function and then ip header is built. 2) What getfrag does? Does it copies actual data in packet? 3)Also can anybody explain me function int ip_build_xmit(struct sock *sk,int getfrag (const void *,char *,unsigned int, unsigned int),const void *frag, unsigned length, struct ipcm_cookie *ipc, struct rtable *rt, int flags) and its parameter usage??? regards, linux_lover __________________________________ Do you Yahoo!? Yahoo! Mail - Helps protect you from nasty viruses. http://promotions.yahoo.com/new_mail - : send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html