[systemd-devel] [networkd] intermittent failure to get DHCP lease on a bond interface

[Leonid Isaev]

Hi,

	Ever since updating to kernel 3.16, systemd-networkd very often fails
to get a DHCPv4 lease on a bond interface. This happens irregularly which makes
me suspect some kind of a race. The bond enslaves eth and wlan cards. Here is
the config:
------
/etc/systemd/network/bond0.netdev
[NetDev]
Name=bond0
Kind=bond

/etc/systemd/network/bond0.network
[Match]
Name=bond0
[Network]
Description=Bond interface
DHCP=v4
[DHCPv4]
UseDNS=false

/etc/systemd/network/eth.network
[Match]
Name=eno1
[Network]
Description=Wired interface
Bond=bond0

/etc/systemd/network/wlan.network
[Match]
Name=wlp3s0
[Network]
Description=Wireless interface
Bond=bond0

$ cat /etc/modprobe.d/bonding.conf 
options bonding mode=active-backup
options bonding primary=eno1
options bonding miimon=1000
------

The wlan interface is managed by wpa_supplicant which is ordered
"After=systemd-networkd.service". There is nothing suspicious in journald and
by running networkd via cmdline with SYSTEMD_LOG_LEVEL=debug (I only see
endless DISCOVER messages):
------
$ journalctl -u systemd-networkd.service 
-- Logs begin at Tue 2014-08-05 10:13:29 EDT, end at Tue 2014-08-05 11:05:07 EDT. --
Aug 05 10:13:29 borei systemd[1]: Starting Network Service...
Aug 05 10:13:29 borei systemd-networkd[446]: bond0           : netdev ready
Aug 05 10:13:29 borei systemd-networkd[446]: lo              : gained carrier
Aug 05 10:13:29 borei systemd-networkd[446]: bond0           : link configured
Aug 05 10:13:29 borei systemd[1]: Started Network Service.
Aug 05 10:13:29 borei systemd-networkd[446]: eno1            : link configured
Aug 05 10:13:29 borei systemd-networkd[446]: wlp3s0          : link configured
Aug 05 10:13:33 borei systemd-networkd[446]: wlp3s0          : gained carrier
Aug 05 10:13:34 borei systemd-networkd[446]: bond0           : gained carrier
------

Interestingly, on the server side (dnsmasq) I see DISCOVER and OFFER messages
for an IP address every 3 sec, but on the client no address is assigned to
bond0.

The bond itself is set up properly. And, of course, dhcpcd _is_ able to obtain
a lease (I can also get a working network by assigning a static IP on the
correct subnet):
------
$ journalctl -u dhcpcd at bond0.service 
-- Logs begin at Tue 2014-08-05 10:13:29 EDT, end at Tue 2014-08-05 11:13:29 EDT. --
Aug 05 10:24:13 borei systemd[1]: Starting dhcpcd on bond0...
Aug 05 10:24:13 borei dhcpcd[916]: version 6.4.3 starting
Aug 05 10:24:13 borei dhcpcd[916]: all: IPv6 kernel autoconf disabled
Aug 05 10:24:13 borei dhcpcd[916]: bond0: adding address fe80::18f7:74d:5764:92e9
Aug 05 10:24:13 borei dhcpcd[916]: if_addaddress6: Operation not supported
Aug 05 10:24:13 borei dhcpcd[916]: error writing DUID: /etc/dhcpcd.duid: Read-only file system
Aug 05 10:24:13 borei dhcpcd[916]: DUID 00:03:00:01:f0:1f:af:4d:36:99
Aug 05 10:24:13 borei dhcpcd[916]: bond0: IAID af:4d:36:99
Aug 05 10:24:14 borei dhcpcd[916]: bond0: rebinding lease of 10.0.0.21
Aug 05 10:24:19 borei dhcpcd[916]: bond0: leased 10.0.0.21 for 86400 seconds
Aug 05 10:24:19 borei dhcpcd[916]: bond0: adding route to 10.0.0.0/24
Aug 05 10:24:19 borei dhcpcd[916]: bond0: adding default route via 10.0.0.1
Aug 05 10:24:19 borei dhcpcd[916]: forked to background, child pid 923
Aug 05 10:24:19 borei systemd[1]: Started dhcpcd on bond0.

$ systemctl cat dhcpcd at bond0.service 
# /usr/lib/systemd/system/dhcpcd at .service
[Unit]
Description=dhcpcd on %I
Wants=network.target
Before=network.target
BindsTo=sys-subsystem-net-devices-%i.device
After=sys-subsystem-net-devices-%i.device

[Service]
Type=forking
PIDFile=/run/dhcpcd-%I.pid
ExecStart=/usr/bin/dhcpcd -q -w %I
ExecStop=/usr/bin/dhcpcd -x %I

[Install]
WantedBy=multi-user.target
------

I am a bit at a loss of how to debug this further... Any ideas?

Thanks,
-- 
Leonid Isaev
GPG fingerprints: DA92 034D B4A8 EC51 7EA6  20DF 9291 EE8A 043C B8C4
                  C0DF 20D0 C075 C3F1 E1BE  775A A7AE F6CB 164B 5A6D
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <http://lists.freedesktop.org/archives/systemd-devel/attachments/20140805/55eeb813/attachment.sig>