interestingly enough, modifying the privacy settings via sysctl has some negative affects if addresses are already up. see diagnosis in bug 1377005 .
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to procps in Ubuntu. https://bugs.launchpad.net/bugs/1068756 Title: IPv6 Privacy Extensions enabled on Ubuntu Server by default Status in “cloud-init” package in Ubuntu: Triaged Status in “procps” package in Ubuntu: Confirmed Bug description: Ubuntu 12.04 LTS and Ubuntu 12.10 server images both ship with the IPv6 Privacy Extensions enabled (as defined in RFC 4941[0]). Not only are they enabled, but these addresses are preferred over addresses obtained using SLAAC. While is may be considered a reasonable default on an image being used on a personal computer, it's not something that is sane to have enabled by default in a server environment. Having this extension enabled can wreak havoc if you are expecting a specific IPv6 address when you know the MAC addresses of your systems beforehand. The file that is responsible for causing this to be defaulted to enabled is: "/etc/sysctl.d/10-ipv6-privacy.conf". This file appears to be part of the procps package (as per the output of 'dpkg -S') and contains the following: # IPv6 Privacy Extensions (RFC 4941) # --- # IPv6 typically uses a device's MAC address when choosing an IPv6 address # to use in autoconfiguration. Privacy extensions allow using a randomly # generated IPv6 address, which increases privacy. # # Acceptable values: # 0 - don’t use privacy extensions. # 1 - generate privacy addresses # 2 - prefer privacy addresses and use them over the normal addresses. net.ipv6.conf.all.use_tempaddr = 2 net.ipv6.conf.default.use_tempaddr = 2 In short, IPv6 privacy extensions should not be enabled by default when deploying an Ubuntu server image. In a server environment you should be able to reliably determine your IPv6 address based on the MAC address of the system. Thank you for taking the time to look in to this as well as consider changing the default behavior of Ubuntu server. -Tim Heckman [0] http://tools.ietf.org/html/rfc4941 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1068756/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
