Netfilter connection tracking

configname: CONFIG_IP_VS_NFCT

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>Network packet filtering framework (Netfilter)
└─>IP virtual server support
└─>Netfilter connection tracking
In linux kernel since version 2.6.37 (release Date: 2011-01-04)  
The Netfilter connection tracking support allows the IPVS
connection state to be exported to the Netfilter framework
for filtering purposes.