I can confirm that IPv6 on Ubuntu 15.10 is basically broken out of the box... at least, the DHCPv6 is broken out of the box due to this issue. The workaround of setting disable_dad worked for me, described at https://www.agwa.name/blog/post/beware_the_ipv6_dad_race_condition
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to isc-dhcp in Ubuntu. https://bugs.launchpad.net/bugs/1447715 Title: dhclient -6: Can't bind to dhcp address: Cannot assign requested address Status in isc-dhcp package in Ubuntu: Confirmed Bug description: After upgrading to Ubuntu 15.04 my computer is unable to obtain an IPv6 address via DHCPv6. The root cause is that dhclient is exiting with the following message: ----------------------------------------------------- Can't bind to dhcp address: Cannot assign requested address Please make sure there is no other dhcp server running and that there's no entry for dhcp or bootp in /etc/inetd.conf. Also make sure you are not running HP JetAdmin software, which includes a bootp server. If you think you have received this message due to a bug rather than a configuration issue please read the section on submitting bugs on either our web page at www.isc.org or in the README file before submitting a bug. These pages explain the proper process and the information we find helpful for debugging.. exiting. ----------------------------------------------------- The problem seems to exist in isc-dhcp-client 4.3.1-5ubuntu2 (15.04 version) because downgrading to isc-dhcp-client 4.2.4-7ubuntu14 (14.10 version) allows me to obtain an address. NetworkManager is the one launching dhclient. The two invocations (one for IPv4 and one for IPv6) are: dhclient_start(): running: /sbin/dhclient -d -q -sf /usr/lib/NetworkManager/nm-dhcp-helper -pf /run/sendsigs.omit.d /network-manager.dhclient-eth0.pid -lf /var/lib/NetworkManager /dhclient-c0a3dfde-5c0b-4cef-9c3b-563cfb1fb9d2-eth0.lease -cf /var/lib/NetworkManager/dhclient-eth0.conf eth0 dhclient_start(): running: /sbin/dhclient -d -q -6 -N -sf /usr/lib/NetworkManager/nm-dhcp-helper -pf /run/sendsigs.omit.d /network-manager.dhclient6-eth0.pid -lf /var/lib/NetworkManager/dhclient6-c0a3dfde-5c0b-4cef-9c3b- 563cfb1fb9d2-eth0.lease -cf /var/lib/NetworkManager/dhclient6-eth0.conf eth0 I do not see anything suspicious with the way both dhclients are invoked. Given that a downgrade allows me to obtain an IPv6 address I think this might be a bug in the ISC DHCP client rather than in NetworkManager. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1447715/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
