So I'm not convinced that doing this in dhclient is necessarily right. Unlike IPv4 where DHCP operates over a raw socket, in IPv6 mode, dhclient is just a regular network client and as such requires a source address to be set so it can contact the network (the link-local address in this case).
As dhclient is supposed to only be triggered after a RA has been received and parsed, it should be the job of whatever handles the RA to wait until a viable link-local has been established before triggering dhclient. That being said, since we don't seem to have anything that handles that first configuration step properly, this workaround certainly won't hurt and will fix the current 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/1633479 Title: dhclient does not wait for ipv6 dad (duplicate address detection) Status in isc-dhcp package in Ubuntu: Confirmed Bug description: dhclient -6 does not wait for an interface go through duplicate address detection. As a result the following will almost always fail: $ dev=eth0 $ ip link set down dev $dev $ dhclient -6 -1 -v eth0 Internet Systems Consortium DHCP Client 4.3.3 Copyright 2004-2015 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ 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.. $ echo $? 1 Related bugs: * bug 1447715: dhclient -6: Can't bind to dhcp address: Cannot assign requested address * bug 1633562: 'dhclient -6 -S' does not bring interface up ProblemType: Bug DistroRelease: Ubuntu 16.10 Package: isc-dhcp-client 4.3.3-5ubuntu15 ProcVersionSignature: Ubuntu 4.8.0-22.24-generic 4.8.0 Uname: Linux 4.8.0-22-generic x86_64 NonfreeKernelModules: zfs zunicode zcommon znvpair zavl ApportVersion: 2.20.3-0ubuntu8 Architecture: amd64 CurrentDesktop: Unity Date: Fri Oct 14 09:18:52 2016 EcryptfsInUse: Yes InstallationDate: Installed on 2015-07-23 (449 days ago) InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Alpha amd64 (20150722.1) SourcePackage: isc-dhcp UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1633479/+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
