Hi Pablo, In pktbuff.c, the doc for pktb_mangle states that "It is appropriate to use pktb_mangle to change the MAC header". This is not true. pktb_mangle always mangles from the network header onwards. I can either: Whithdraw the offending doc items OR: Adjust pktb_mangle to make the doc correct. This involves changing pktb_mangle, nfq_ip_mangle and (soon) nfq_ip6_mangle. The changes would be a no-op for AF_INET and AF_INET6 packet buffers. What do you think? Cheers ... Duncan.