"hl" hoplimit/TTL match support

modulename: xt_hl.ko

configname: CONFIG_NETFILTER_XT_MATCH_HL

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>Network packet filtering framework (Netfilter)
└─>Core Netfilter Configuration
└─>"hl" hoplimit/TTL match support
In linux kernel since version 2.6.30 (release Date: 2009-06-09)  
HL matching allows you to match packets based on the hoplimit
in the IPv6 header, or the time-to-live field in the IPv4
header of the packet.

source code: