hi Micha, while studying how ping packet formed and send to adjecent machine when i ping to that machine i found that from icmp.c control goes to ip_build_xmit in ip_output.c but i am unable to find alloc_skb that allocates space for ping packet. the sock_alloc_skb_send in ip_build_xmit_slow have that alloc_skb function call but it is allocating only hh_len. so where kernel allocates space for ping packet? regards, parag.