This creates an LED-trigger that can then be attached to system indicator

lights, to blink or illuminate them when certain packets pass through the

system. One example might be to light up an LED for a few minutes every time

an SSH connection is made to the local machine. The following options control

the trigger behavior:

.TP

\fB\-\-led\-trigger\-id\fP \fIname\fP

This is the name given to the LED trigger. The actual name of the trigger

will be prefixed with "netfilter-".

.TP

\fB\-\-led-delay\fP \fIms\fP

This indicates how long (in milliseconds) the LED should be left illuminated

when a packet arrives before being switched off again. The default is 0

(blink as fast as possible.) The special value \fIinf\fP can be given to

leave the LED on permanently once activated. (In this case the trigger will

need to be manually detached and reattached to the LED device to switch it

off again.)

.TP

\fB\-\-led\-always\-blink\fP

Always make the LED blink on packet arrival, even if the LED is already on.

This allows notification of new packets even with long delay values (which

otherwise would result in a silent prolonging of the delay time.)

.TP

Example:

.TP

Create an LED trigger for incoming SSH traffic:

iptables \-A INPUT \-p tcp \-\-dport 22 \-j LED \-\-led\-trigger\-id ssh

.TP

Then attach the new trigger to an LED:

echo netfilter\-ssh >/sys/class/leds/\fIledname\fP/trigger