[ipv6hackers] Host tracking in IPv6 (SI6 IPv6 toolkit v1.3.3)

Karl Auer kauer at biplane.com.au
Tue Mar 12 05:31:32 CET 2013

On Mon, 2013-03-11 at 23:31 -0400, Fernando Gont wrote:
> > How does known-iids help you with the tracking of systems with privacy
> > extensions?
> Privacy addresses don't help you at all, since they are generated *in
> addition* to the other addresses. SO, when you want to track a node, you
> simply forget about the privacy addresses, and always poll/probe the
> "stable" one.

Assuming you know the stable one. You may be able to find it via hinted
scanning, but if the node does not use the stable address to
communicate, then the stable address will not be exposed to be traced. I
realise this is security through obscurity ;-)

I'd like to see another value added to the /proc/sys/net/ipv6/conf
directory in Linux that turns OFF autoconf when temp addresses are in
use. Perhaps a fourth value for use_tempaddr:
   0 = do not use temporary addresses
   1 = use temporary addresses, but prefer non-temporary
   2 = use temporary addresses and prefer temporary addresses
   3 = use temporary addresses and do not configure non-temporary

Because this is per-interrface, this is less useful for hosts that have
multiple prefixes on interfaces; I may be quite happy to use a
non-temporary address out of one prefix for internal communications, but
want to use only temporary addresses from another prefix for external
communications. At present, I need (on Linux at least) to configure
temporary and non-temporary addresses from both prefixes, even though I
will be using only one of each. One solution - an ugly one - is to
filter the prefix or even the addresses on the router or at the network

Regards, K.

Karl Auer (kauer at biplane.com.au)

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