This issue seems to have been resolved in Xenial as a side-effect of changing to systemd, as systemd-sysctl.service runs before NetworkManager.service and networking.service. When those services configure a device-specific use_tempaddr sysctl, it will be left alone.
-- 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/1497166 Title: procps' 10-ipv6-privacy.conf stomps on the ifup/NetworkManager "privext"/"ipv6.ip6-privacy" settings Status in ifupdown package in Ubuntu: New Status in network-manager package in Ubuntu: New Status in procps package in Ubuntu: New Bug description: I have configured the following in /etc/network/interfaces: auto eth0 iface eth0 inet6 auto privext 0 According to interfaces(5), this should disable IPv6 Privacy Extensions. However, after booting the machine, /proc/sys/net/ipv6/conf/eth0/use_tempaddr contains the value "2" - which means that Privacy Extensions are enabled. However running "ifdown eth0; ifup eth0" does fix the problem, so it is clear that ifup(8) does correctly set the use_tempaddr sysctl when bringing up the interface. What's going on is that sometime later in the bootup process, the procps package overrides the user-configured value and sets it unconditionally to "2" for every interface on the system. This happens because the file /etc/sysctl.d/10-ipv6-privacy.conf contains "net.ipv6.conf.all.use_tempaddr = 2". It should not, or this bug should be reassigned to the ifupdown package requesting for the removal of the defunct "privext" setting. On a related node, enabling IPv6 Privacy Extensions by default is counter to RFC 4941's recommendations. Quoting from section 3.6 Deployment Considerations: The use of temporary addresses may cause unexpected difficulties with some applications. As described below, some servers refuse to accept communications from clients for which they cannot map the IP address into a DNS name. In addition, some applications may not behave robustly if temporary addresses are used and an address expires before the application has terminated, or if it opens multiple sessions, but expects them to all use the same addresses. Consequently, the use of temporary addresses SHOULD be disabled by default in order to minimize potential disruptions. Individual applications, which have specific knowledge about the normal duration of connections, MAY override this as appropriate. As such, the most appropriate course of action is probably to stop shipping the 10-ipv6-privacy.conf file by default. The described behaviour is observed on Trusty LTS. Tore To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/1497166/+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
