Race condition on pppoe on boot

[Nigel Hathaway]

From the syslog during boot:

Dec 4 16:38:15 jeeves pppd[1447]: Plugin rp-pppoe.so loaded.
Dec 4 16:38:15 jeeves ifup[469]: Plugin rp-pppoe.so loaded.
Dec 4 16:38:15 jeeves kernel: [ 19.088373] PPP generic driver version 2.4.2
Dec 4 16:38:15 jeeves pppd[1452]: pppd 2.4.7 started by root, uid 0
Dec 4 16:38:15 jeeves ifup[469]: Cannot find device "ppp0"
Dec 4 16:38:15 jeeves kernel: [ 19.164193] NET: Registered protocol family 24
Dec 4 16:38:15 jeeves ifup[469]: Failed to bring up dsl-provider.
Dec 4 16:38:15 jeeves pppd[1452]: PPP session is 914
Dec 4 16:38:15 jeeves pppd[1452]: Connected to a0:f3:e4:34:64:25 via interface vlan4
Dec 4 16:38:15 jeeves pppd[1452]: Using interface ppp0
Dec 4 16:38:15 jeeves pppd[1452]: Connect: ppp0 <--> vlan4
Dec 4 16:38:15 jeeves systemd-udevd[1504]: link_config: autonegotiation is unset or enabled, the speed and duplex are not writable.
Dec 4 16:38:15 jeeves systemd[1]: networking.service: Main process exited, code=exited, status=1/FAILURE
Dec 4 16:38:15 jeeves pppd[1452]: Terminating on signal 15
Dec 4 16:38:15 jeeves pppd[1452]: Connection terminated.
Dec 4 16:38:15 jeeves pppd[1452]: Sent PADT
Dec 4 16:38:15 jeeves pppd[1452]: Exit.
Dec 4 16:38:15 jeeves systemd[1]: networking.service: Failed with result 'exit-code'.
Dec 4 16:38:15 jeeves systemd[1]: Failed to start Raise network interfaces.

You can see that it gives up on ppp0 being ready before giving it a chance to actually be ready

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: pppoe 3.11-0ubuntu1
Uname: Linux 4.14.85-152 armv7l
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: armhf
Date: Tue Dec 4 17:02:51 2018
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: rp-pppoe
UpgradeStatus: No upgrade log present (probably fresh install)
modified.conffile..etc.ppp.peers.dsl-provider: [deleted]

[Nigel Hathaway (nhathaway)]

From /etc/network/interfaces (not using systemd networking)

auto dsl-provider
iface dsl-provider inet ppp
        pre-up /bin/ip link set vlan4 up # line maintained by pppoeconf
        provider dsl-provider

The non-commented-out lines from /etc/ppp/peers/dsl-provider (generated using pppoeconf)

user "xxxxxxxxx"
noipdefault
defaultroute
replacedefaultroute
hide-password
lcp-echo-interval 20
lcp-echo-failure 3
connect /bin/true
noauth
persist
mtu 1500
maxfail 0
holdoff 10
+ipv6 ipv6cp-use-ipaddr
plugin rp-pppoe.so vlan4
noaccomp
default-asyncmap
nic-vlan4

[Nigel Hathaway (nhathaway)]

Note: "pon dsl-provider" works after boot

[Nigel Hathaway (nhathaway)]

I've found what looks like a possible cause.

In /etc/network/interfaces under iface dsl-provider inet ppp, I also had an up/post-up clause which referenced ppp0

   post-up ..... ppp0 .....

It would seem that for type 'ppp', up and post-up get called before ppp0 is actually up. This is also mentioned here:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=127786;msg=30

I haven't tried the 'updetach' as this suggests. I have just removed the post-up referencing ppp0.