These are Iptables (Netfilter) PROMISC chain patches by Gianni Tedesco (
adopted to 2.4.9 kernel and iptables 1.2.3.

iptables-promisc-chain-2.4.9.diff - kernel patch
orig/promisc.iptables.patch - iptables patch
iptables-1.2.3-libiptc-promisc-chain.diff - additional iptables patch if you want working libiptc

Gianni description:
PROMISC Chain. netfilter and iptables patches that add a new chain to the filter table called PROMISC.
Packets that get picked up in promiscuous mode and arent destined for our host traverse this chain.
This is useful so we can monitor all taffic on our LAN segment. You can use the REJECT target to send
out RSTs to stop TCP streams between other machines.

Note, that packets picked by INPUT chain do not traverse PROMISC chain.