Folks,
I created a script to keep a persistent "emergency" connection with a 3G modem, so I can access my CentOS 7 makeshift server remotely if the usual network fails. Everything works for a few seconds, but then somebody kills pppd with a SIGTERM:
Jul 08 17:03:29 helicarrier systemd[1]: Starting Network Manager Script Dispatcher Service...
Jul 08 17:03:29 helicarrier dbus-daemon[605]: dbus[605]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher'
Jul 08 17:03:29 helicarrier dbus[605]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher'
Jul 08 17:03:29 helicarrier systemd[1]: Started Network Manager Script Dispatcher Service.
Jul 08 17:03:29 helicarrier nm-dispatcher[12292]: Dispatching action 'up' for ppp0
Jul 08 17:03:29 helicarrier chronyd[616]: Source 146.164.48.5 online
Jul 08 17:03:29 helicarrier chronyd[616]: Source 5.9.110.236 online
Jul 08 17:03:29 helicarrier chronyd[616]: Source 192.99.2.8 online
Jul 08 17:03:29 helicarrier chronyd[616]: Source 200.192.232.8 online
Jul 08 17:03:53 helicarrier pppd[12279]: Terminating on signal 15
Jul 08 17:03:53 helicarrier pppd[12279]: Child process pppd (charshunt) (pid 12280) terminated with signal 15
Jul 08 17:03:53 helicarrier pppd[12279]: Modem hangup
Jul 08 17:03:53 helicarrier pppd[12279]: Connect time 0.4 minutes.
Jul 08 17:03:53 helicarrier pppd[12279]: Sent 4817 bytes, received 1170 bytes.
Jul 08 17:03:53 helicarrier pppd[12279]: Script /etc/ppp/ip-down started (pid 12323)
Jul 08 17:03:53 helicarrier pppd[12279]: Connection terminated.
Jul 08 17:03:53 helicarrier NetworkManager[702]: <info> (ppp0): device state change: activated -> unmanaged (reason 'removed') [100 10 36]
Jul 08 17:03:53 helicarrier NetworkManager[702]: <info> (ppp0): deactivating device (reason 'removed') [36]
Jul 08 17:03:53 helicarrier NetworkManager[702]: <info> NetworkManager state is now CONNECTED_LOCAL
Jul 08 17:03:53 helicarrier dbus-daemon[605]: dbus[605]: [system] Activating via systemd: service name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm...er.service'
Jul 08 17:03:53 helicarrier dbus[605]: [system] Activating via systemd: service name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.service'
To make the things more readable, this is the relevant line:
Jul 08 17:03:53 helicarrier pppd[12279]: Connection terminated.
How can I trace down the program which is sending this kill? NetworkManager is my primary suspect, but I don't think it should mess with my connections as I haven't used it to connect anyway (I'm using my own old-style pppd + chat script and some tricks to keep the connection always on).
