Auto enbale/disable ping request of gateway, for router check gateway avaliable.

vpnc-enable-disable-ping.sh

/etc/vpnc/post-connect.d/enable-ping.sh 
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#!/bin/bash

echo "Connected.";
# enable host ping
while [ ! -z "$(iptables -L | grep icmp-net-unreachable)" ]; do 
	echo "==> delete icmp-net-unreachable";
	iptables -D INPUT -p icmp -m icmp --icmp-type echo-request -j REJECT --reject-with icmp-net-unreachable;
done

echo "Ping enabled.";


/etc/vpnc/disconnect.d/disable-ping.sh 
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#!/bin/bash

echo "Disconnected.";
# disable host ping
[ -z "$(iptables -L | grep icmp-net-unreachable)" ] && {
	iptables -A INPUT -p icmp -m icmp --icmp-type echo-request -j REJECT --reject-with icmp-net-unreachable;
}

echo "Ping disabled.";