In a network that uses stateless autoconfiguration with router advertisements, every node will assign to itself a unique IP address. Our current config uses the MAC address as par of this unique IP address. Using the MAC address uniquely identifies a certain computer, parties you connect to can use it to track your location even without the use of cookies. IPv6 Privacy Extensions can be used to randomize the IP address that is used for outgoing connections, making it unsuitable for tracking. Linux supports this, but unlike Windows, under Linux it is not enabled by default. Please enable this by default, by adding the following line to sysctl.conf: net.ipv6.conf.all.use_tempaddr = 2
Is there any reason we wouldn't want to set this on the kernel side?
The biggest reason to not enable this by default in the kernel is that there is no support for that. --Quote-- Privacy Extensions for Stateless Address Autoconfiguration in IPv6 support. With this option, additional periodically-altered pseudo-random global-scope unicast address(es) will be assigned to your interface(s). We use our standard pseudo-random algorithm to generate the randomized interface identifier, instead of one described in RFC 3041. By default the kernel does not generate temporary addresses. To use temporary addresses, do echo 2 >/proc/sys/net/ipv6/conf/all/use_tempaddr See <file:Documentation/networking/ip-sysctl.txt> for details. --/Quote-- Besides that, to not be so different from other distro's I would recommend enabling it in /etc/sysctl.conf.
Please don't do this insane thing. Let the registered tinfoil-hat wearers set it, but leave reverse DNS and sane behaviour working for the rest of us. NM should have a way for those users to enable it though; let's close this bug as a duplicate of bug 828931 *** This bug has been marked as a duplicate of bug 828931 ***