====== how to hide your MAC address ======
with a kernel compiled with : CONFIG_IPV6_PRIVACY=y

do :
<code>
#as root
echo 2 >/proc/sys/net/ipv6/conf/all/use_tempaddr
</code>

to make it effective restart your network interface

to make it persistent add to your /etc/sysctl.conf
<code>
net.ipv6.conf.all.use_tempaddr=2
</code>