Activity log for bug #1533631

Date Who What changed Old value New value Message
2016-01-13 11:37:51 Alexey Zagarin bug added bug
2016-03-22 17:00:39 Launchpad Janitor network-manager (Ubuntu): status New Confirmed
2016-03-22 17:00:42 TJ bug added subscriber TJ
2016-03-30 19:30:54 TJ network-manager (Ubuntu): importance Undecided High
2016-03-30 19:31:22 TJ bug task added isc-dhcp (Ubuntu)
2016-03-30 19:31:45 TJ isc-dhcp (Ubuntu): importance Undecided High
2016-03-30 19:31:45 TJ isc-dhcp (Ubuntu): status New Triaged
2016-03-30 23:14:53 TJ network-manager (Ubuntu): status Confirmed Triaged
2016-03-31 00:50:22 TJ attachment added Network Manager TRACE debug log https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1533631/+attachment/4617754/+files/nm-debug.log
2016-03-31 11:07:07 TJ isc-dhcp (Ubuntu): importance High Low
2016-03-31 11:07:26 TJ isc-dhcp (Ubuntu): status Triaged Invalid
2016-03-31 12:04:06 TJ bug watch added https://bugzilla.gnome.org/show_bug.cgi?id=748268
2016-03-31 12:04:06 TJ bug task added network-manager
2016-03-31 12:23:58 TJ description After fixing IPv6 address assignment (#1469346), IPv6 works fine until sleep. On wake up ubuntu fails to renew its IPv6 lease: Jan 13 10:47:47 ubuntu dhclient: PRC: Renewing lease on wlp3s0. Jan 13 10:47:47 ubuntu dhclient: PRC: Rebinding lease on wlp3s0. Jan 13 10:47:47 ubuntu dhclient: XMT: Rebind on wlp3s0, interval 9890ms. Jan 13 10:47:47 ubuntu NetworkManager[796]: <info> (wlp3s0): DHCPv6 state changed bound -> unknown Jan 13 10:47:47 ubuntu dhclient: PRC: Address 2a02:xxxx:xxxx:xxxx::b44 depreferred. Jan 13 10:47:47 ubuntu NetworkManager[796]: <info> (wlp3s0): DHCPv6 state changed unknown -> expire Jan 13 10:47:47 ubuntu NetworkManager[796]: <info> (wlp3s0): canceled DHCP transaction, DHCP client pid 1170 Jan 13 10:47:47 ubuntu NetworkManager[796]: <info> (wlp3s0): DHCPv6 state changed expire -> done I'm not sure that it's solely NetworkManager issue (dhclient could also be affected). Network Manager summarily kills the IPv6 dhclient process when the DHCPv6 lease contained in the dhclient6-${UUID}.lease file is out-of date, leaving the IPv6 interface without a stateful IPv6 address, or, if the "require IPv6 address on this interface" option is enabled, causes NM to cycle continuously deactivating and reactivating the interface (including the IPv4 addresses). This is effectively a Denial Of Service. It can be trivially induced if, for example, the dhclient6-$(UUID}.lease file contains a lease that was issued before the user went away on vacation or the PC wasn't connected to the same network for a few days (depending on the lease renew/rebind/expiry times). Calculation on the old lease of start + preferred_lifetime < NOW triggers dhclient to 'DEPREFER6' the lease (withdraw the address record) and ask the DHCPv6 server for a new lease, but Network Manager will kill the dhclient because it only sees an 'EXPIRE6' state change. In summary, when the DHCPv6 state transitions from "bound" to "unknown" then "expire" to "done" Network Manager kills the 'dhclient' process before it has chance to request and bind a fresh lease, If 'dhclient' is run manually with the same command-line options and allowed to continue running it correctly gains a new lease. Network Manager doesn't know how to handle "DEPREF6", which is sent from isc-dhcp dhclient to the helper script (set by "-sf" option). So it seems that to correctly solve this issue Network Manager must be taught how to handle DEPREF6. /var/log/syslog will show a message from dhclient of the form: dhclient: PRC: Address 2a02:8011:2007::2 depreferred.
2016-03-31 12:59:01 Bug Watch Updater network-manager: status Unknown Confirmed
2016-03-31 12:59:01 Bug Watch Updater network-manager: importance Unknown Medium
2016-03-31 13:18:28 TJ summary Failed to renew DHCPv6 lease after suspend dhclient killed when DHCPv6 lease is out-of date
2016-03-31 13:23:55 TJ network-manager (Ubuntu): assignee TJ (tj)
2016-03-31 13:23:59 TJ network-manager (Ubuntu): status Triaged In Progress
2016-04-01 16:43:49 TJ isc-dhcp (Ubuntu): status Invalid In Progress
2016-04-01 16:43:52 TJ isc-dhcp (Ubuntu): importance Low High
2016-04-01 16:43:57 TJ isc-dhcp (Ubuntu): assignee TJ (tj)
2016-11-14 06:25:54 Klaus Kudielka bug added subscriber Klaus Kudielka
2016-12-26 20:01:10 Oleg bug added subscriber Oleg
2017-02-20 22:27:18 Douglas Thrift bug added subscriber Douglas Thrift
2018-03-16 04:25:30 Bug Watch Updater network-manager: status Confirmed Fix Released
2020-10-31 15:53:21 Alexey Ermilov bug added subscriber Alexey Ermilov
2024-09-14 09:53:41 TJ isc-dhcp (Ubuntu): assignee TJ (tj)
2024-09-14 09:53:44 TJ network-manager (Ubuntu): assignee TJ (tj)