#12482 NORM Not Tri: Support IPv6 privacy extensions (pseudo-randomized IPv6 address)

Zarro Boogs per Child bugtracker at laptop.org
Fri Jan 18 22:54:01 EST 2013

#12482: Support IPv6 privacy extensions (pseudo-randomized IPv6 address)
 Reporter:  greenfeld    |                 Owner:                                   
     Type:  enhancement  |                Status:  new                              
 Priority:  normal       |             Milestone:  Not Triaged                      
Component:  kernel       |               Version:  Development build as of this date
 Keywords:               |           Next_action:  diagnose                         
 Verified:  0            |   Deployment_affected:                                   
Blockedby:               |              Blocking:                                   
 In IPv6, a computer can have more than one IPv6 address.  And on networks
 where IPv6 auto-configuration is used, the last /64 of the primary address
 used for both initiating and receiving communications on XOs is a fixed
 value based on the MAC address of the device.

 This is a privacy risk, because these 64-bits are exposed to the Internet
 (IPv6 is not typically NAT'd although it can be DHCPv6'd), stay the same
 as the system moves subnets, and therefore uniquely identify the system
 almost anywhere on the Internet.  Many desktop-oriented operating systems
 which support IPv6 therefore enable by default a form of pseudo-randomized
 IPv6 address creation such as RFC 4941, using said address for outgoing
 connections.  This pseudo-random address is then changed periodically,
 typically on startup as well as every 24 hours.

 Windows Vista & higher do this by default.  Fedora has the kernel option
 to do a variant of RFC 4941 but does not seem to make this the default
 (although I could have sworn I saw a Fedora system doing this without me
 asking it to).

 OLPC currently does not compile its Linux kernels with the option to allow
 this to be done (CONFIG_IPV6_PRIVACY=y) nor enable it by default
 (interface "use_tempaddr" sysctls, or via NetworkManager). However we
 should at least match Fedora and include the kernel option to allow others
 to enable this if desired.

Ticket URL: <http://dev.laptop.org/ticket/12482>
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