pppd persistent mode is not working

[Gombo Tsydynzhapov]

Binary package hint: upstart

After upgrading Ubuntu Server from 8.04 LTS to 10.04 LTS persistent mode dialing for pppd is broken.

I have a VPN setup over PPTP using pppd.
From syslog, after the connection is lost for whatever reason (here plug was disconnected):

pptp[986]: anon log[pptp_handle_timer:pptp_ctrl.c:1050]: closing control connection due to missing echo reply
pptp[986]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 12 'Call-Clear-Request'
pptp[986]: anon log[pptp_conn_close:pptp_ctrl.c:430]: Closing PPTP connection
pptp[986]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 3 'Stop-Control-Connection-Request'
pptp[986]: anon log[call_callback:pptp_callmgr.c:79]: Closing connection (call state)
pppd[954]: Modem hangup
pppd[954]: Connect time 3.0 minutes.
pppd[954]: Sent 18851 bytes, received 12102 bytes.
pppd[954]: Connection terminated.
pppd[954]: Terminating on signal 15
pppd[954]: Exit.

pppd exits and never tries to dial again.

The bug is apparently similar to https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/78043 and https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/396804, but now it is caused by pppd0 device being brought down by network-interface upstart job instead of udev.
Indeed, editing /etc/udev/rules.d/85-ifupdown.rules to exclude "remove" action completely has no effect, but editing last line of network-interface.conf to read

post-stop exec ifdown --allow hotplug $INTERFACE

work this bug around.
Probably, this is no solution, since in practice, as far as I understand, ifdown is never get called for any interface, but I don't know better.

[Christian Hudon (chrish)]

I'm having the same problem. I ended up renaming the network-interface.conf file to *.disabled as this is a server and all network interfaces are static and persistent (i.e. I don't want them to go down unless I say "ifdown foo" on the command-line).

[Craig Ringer (ringerc)]

It looks like /etc/init/network-interface.conf from ifupdown should probably exclude ppp interfaces. It appears to be intended for hotplug, and ppp interfaces look like they're hotplugged, but in fact they're typically created as a result of an ifup invoking pppd. They need a way to be protected from automatic ifdown if they're persistent.

Adding ifupdown to the bug.

[Alexey Osipov (lion-simba)]

Confirm the bug.

Strange that project https://launchpad.net/ifupdown is very new (registered 2010-08-07). Could we more precisely state, that bug is in ifupdown _Ubuntu_ package?

[Scott James Remnant (scott)]

It seems that this has been assigned to the upstream Upstart project without a rationale for why this is not a bug in the Ubuntu configuration. Unless you're sure there is an /sbin/init *code bug*, the correct place for bug reports, even about boot, is in the appropriate Ubuntu package.

This seems to be already assigned to ppp (Ubuntu) so you may need to do nothing