Stateless NAT

modulename: act_nat.ko

configname: CONFIG_NET_ACT_NAT

Linux Kernel Configuration
└─>Networking
└─>Networking options
└─>QoS and/or fair queueing
└─>Stateless NAT
In linux kernel since version 2.6.24 (release Date: 2008-01-24)  
Say Y here to do stateless NAT on IPv4 packets. You should use
netfilter for NAT unless you know what you are doing.

To compile this code as a module, choose M here: the
module will be called nat.

source code: