Connection mark tracking support

configname: CONFIG_NF_CONNTRACK_MARK

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>Network packet filtering framework (Netfilter)
└─>Core Netfilter Configuration
└─>Connection mark tracking support
In linux kernel since version 2.6.15 (release Date: 2006-01-02)  
This option enables support for connection marks, used by the
`CONNMARK' target and `connmark' match. Similar to the mark value
of packets, but this mark value is kept in the conntrack session
instead of the individual packets.