A sysctl Linux variable to change randomly
temporary the PC mac address for IPv6 and increase anonymity on
IPv6 networks
To prevent tracking and increase anonymity in IPv6 networks the
Linux kernel has a variable to change randomly the MAC identifier.
This feature will be very useful in terms of security in the short
future, when all the IPv4 IP addresses are finished. The UIE
(Extended Unified Udentifier) for an ipv6 address can be changed
with command:
sysctl -w net.ipv6.conf.all.use_tempaddr=2
Microsoft Windows Vista and Windows 7 has the UIE enabled by
default, enabling the random MAC changes automatically for a host
cvan be done as usual by adding the
net.ipv6.conf.all_use_tempaddr=2 to
/etc/sysctl.conf
On an IPv6 network every
ifconfig eth0 down and
ifconfig
eth0 up will instruct the lan card to be set a different MAC
address for the ipv6 ip on the interface.
Changing the UIE randomly however also have security downsides if
the host gets infected with a Virus or Worm. The security downsides
of the enabled UIE affects mainly Windows hosts on IPv6 networks as
UIE variable is enabled by default there. I've found this great tip
in an article in the latest
Linux Magazine October 2011. Its
the first time I saw a paper
Linux Magazine, the magazine
contains a lot of helpful info on the latest Linux developments and
latest trends in the Linux world. Subscription to receive the
magazine via normal post is for the magazine costs 6.65 EUR per
month (80 EUR) yearly. The 80 euro yearly includes 12 CDS (each
magazine is bundled with a newly launched new version of a Linux
distribution).
There is also a cheaper subscription for the magazine which costs
64.90 EUR.