Network Address Translation support

modulename: nf_nat.ko

configname: CONFIG_NF_NAT

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>Network packet filtering framework (Netfilter)
└─>Core Netfilter Configuration
└─>Network Address Translation support
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
The NAT option allows masquerading, port forwarding and other
forms of full Network Address Port Translation. This can be
controlled by iptables, ip6tables or nft.

source code:
net/netfilter/