Dnsmasq config

Add into file /etc/dnsmasq.conf
resolv-file=/etc/resolv.conf.dnsmasq
If the dnsmasq is running at the router/gateway, add the following into file /etc/dhclient-enter-hooks
CUSTOM_RESOLV_CONF=/etc/resolv.conf.dnsmasq
make_resolv_conf() {
echo "doing nothing to resolv.conf"

if [ -n "$new_domain_name_servers" ]; then
/bin/rm $CUSTOM_RESOLV_CONF
[ -n "$new_domain_name" ] && echo search $new_domain_name >$CUSTOM_RESOLV_CONF
for nameserver in $new_domain_name_servers; do
echo nameserver $nameserver >> $CUSTOM_RESOLV_CONF
done
fi
}

Othewise add the following into file /etc/dhclient-enter-hooks
make_resolv_conf() {
echo "doing nothing to resolv.conf"
}