Manpages

NAME

nfct - command line tool to configure with the connection tracking system

SYNOPSIS

nfct command subsystem [parameters]

DESCRIPTION

nfct is the command line tool that allows you to configure the Connection Tracking System.

COMMANDS

disable

This command is for the helper subsystem. It allows you to disable enqueueing packets to userspace for helper inspection.

default-set

This command is for the timeout subsystem. It allows you to set default protocol timeouts.

default-get

This command is for the timeout subsystem. It allows you to get the default protocol timeouts.

SUBSYS

By the time this manpage has been written, the supported subsystems are timeout and helper.
timeout

The timeout subsystem allows you to define fine-grain timeout policies.

version

Displays the version information.

EXAMPLE

nfct add timeout test-tcp inet tcp established 100 close 10 close_wait
10
This creates a timeout policy for tcp using 100 seconds for the
ESTABLISHED state, 10 seconds for CLOSE state and 10 seconds for the
CLOSE_WAIT state.
Then, you can attach the timeout policy with the iptables CT target:
iptables -I PREROUTING -t raw -p tcp -j CT --timeout test-tcp
iptables -I OUTPUT -t raw -p tcp -j CT --timeout test-tcp
You can test that the timeout policy with:
conntrack -E -p tcp
It should display:
[UPDATE] tcp 6 100 ESTABLISHED src=192.168.39.100 dst=57.126.1.20
sport=56463 dport=80 src=57.126.1.20 dst=192.168.39.100 sport=80
dport=56463 [ASSURED]

SEE ALSO

iptables(8),conntrack(8)

BUGS

Please, report them to netfilter-devel [AT] vger.org or file a bug in Netfilter’s bugzilla (https://bugzilla.netfilter.org).

AUTHORS

Pablo Neira Ayuso wrote and maintains the nfct tool.

Man page written by Pablo Neira Ayuso <pablo [AT] netfilter.org>.