On Saturday, September 26, 2015, David Hubbard < dhubbard@dino.hostasaurus.com> wrote:
Hey all, as we've slowly deployed IPv6 to our end users, it has begun to cause some issues for those on Mac's specifically. Apple apparently has an algorithm at some point in the network stack to decide whether IPv4 or IPv6 is, perhaps, 'better' or 'faster' at any given point in time during an ongoing session. This allows a computer talking to a dual stack remote website to flip flop between v4 and v6 as activity is conducted.
Websites that require some type of authentication that is handled via session cookies have been booting our users out randomly with "your ip address has changed" type message. This occurs when their Mac decides to switch between protocols because the site views it as a session hijacking attempt when Joe User with session ID xyz switches from 192.0.2.10 to 2001:db8::1:1:a or vice versa.
Has anyone run into this? Our users on other platforms don't seem to have this issue; linux and MS desktops seem to just use v6 if it's available and v4 if not.
Thanks,
David
Info about Apple and their unique IPv6 selection process https://www.ietf.org/mail-archive/web/v6ops/current/msg22455.html