[ipv6pixie]

Doesn't IPv6 also mean the permanent death of privacy? Think about it. IPv6 kills all the stupid NAT schemes IPv4 required. Everyone gets a permanent static IP address. Your browser delivers it to every site you visit. It's the ultimate permanent cookie. Of course Google is so happy for this.

[Arnt]

No, you don't get a permanent static IP address. That depends on the ISP. And even if your ISP hands out permanent addresses, your devices can change addresses often. Most of my devices do change addresses, and I didn't have to turn it on.

Both v6 and the linux stack are privacy-friendly.

[chimeracoder]

> Both v6 and the linux stack are privacy-friendly.

Yes and no.

The privacy extensions will create new addresses, but they will always belong to the same /64. To my knowledge, TWC will allocate a /64, but there's no guarantee that power cycling your modem will generate a new /64[0]. I believe other ISPs work the same way - they may give you a new /64, but they're not required to and don't guarantee it in the SLA. And most people won't power cycle their modems often anyway, which means they could have the same /64 for months on end.

If we're talking about online tracking, it's very easy for trackers to just throw their hands up and treat all addresses within a /64 as if they represent a single user + device. This isn't completely accurate, but it's no less accurate than IP address tracking with IPv4.

Furthermore, I am unaware of any reliable commercial VPN providers that currently provide IPv6 connections (at least over OpenVPN[1]), so if you have dual-stack connectivity, your IPv6 connection can compromise your privacy even for your IPv4 connection[2].

[0] Technically this is true for ipv4 as well, but due to the relative scarcity of addresses you're less likely to get a pseudo-static ipv4 address.

[1] OpenVPN now supports IPv6 clients, though I don't know of any actual deployments of this. PPTP is IPv4-only.

[2] I think this blog post is sadly still accurate: https://blog.dave.io/2011/06/vpn-ipv6-privacy/

[Arnt]

Well, I have two consumer DSL connections at home from different ISPs with completely independent infrastructure (a few billable hours pays for a year's redundancy). Both of them behave give me new, unpredictable v6 prefixes via DHCP every 2h/1d.

So obviously not all other ISPs work the way yours does.

[crazy8s]

So, you are dependent on the ISP cooperating to give you privacy? What could possibly go wrong? Downvote me all you like guys. This just proved my point. NSA will love IPv6 adoption.

[Arnt]

Sure. We're dependent just like we were on IPv4, except that the ISPs' address pools are bigger. The same things can go wrong.

[samuelsmith]

That sounds a bit disingenuous. IPv4 was always on a forced rotation because a) limited address space and b) ISPs wanted to milk customers for static IP charges. IPv6 eliminates a). That leaves b) which isn't really a factor on mobile devices. It really is a permanent cookie if the ISP decides to implement it that way. I can't say I trust AT&T and Verizon after their 'header enrichment' shenanigans.

[kalleboo]

http://en.wikipedia.org/wiki/IPv6#Privacy

  When privacy extensions are enabled, the operating system 
  generates random host identifiers to combine with the 
  assigned network prefix


  Privacy extensions are enabled by default in Windows 
  (since XP SP1), OS X (since 10.7), and iOS (since version 
  4.3).[32][33] Some Linux distributions have enabled 
  privacy extensions as well.[34]

[wmf]

That's why OSes use privacy addresses.

[blfr]

Privacy addresses still come from the same /64 which works a lot like a single IPv4 for home deployments. So from the privacy perspective IPv6 is like giving every home router a static IPv4 address.

Of course, there is no technical requirement to make those addresses static. It's just how they're usually assigned because it's more convenient.