Перестал работать pptp клиент

[ИзБывших]

Есть pptp сервер. Работает уже давно. Все клиенты к нему вполне нормально подключаются с форточек. С какого-то момента клиент на UBUNTU перестал подключаться.
Крайне редко подключение всё-таки проходит, но в подавляющем большинстве случаев идёт сообщение о сбое VPN подключения.
Лог:

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Dec 22 13:37:34 localhost NetworkManager[895]: <info> Starting VPN service 'pptp'...
Dec 22 13:37:34 localhost NetworkManager[895]: <info> VPN service 'pptp' started (org.freedesktop.NetworkManager.pptp), PID 6658
Dec 22 13:37:34 localhost NetworkManager[895]: <info> VPN service 'pptp' appeared; activating connections
Dec 22 13:37:34 localhost NetworkManager[895]: <info> VPN plugin state changed: starting (3)
Dec 22 13:37:34 localhost NetworkManager[895]: <info> VPN connection 'pptp Office' (Connect) reply received.
Dec 22 13:37:34 localhost pppd[6663]: Plugin /usr/lib/pppd/2.4.5/nm-pptp-pppd-plugin.so loaded.
Dec 22 13:37:34 localhost pppd[6663]: pppd 2.4.5 started by root, uid 0
Dec 22 13:37:34 localhost pptp[6668]: nm-pptp-service-6658 log[main:pptp.c:314]: The synchronous pptp option is NOT activated
Dec 22 13:37:34 localhost pppd[6663]: Using interface ppp0
Dec 22 13:37:34 localhost pppd[6663]: Connect: ppp0 <--> /dev/pts/1
Dec 22 13:37:34 localhost NetworkManager[895]:    SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/ppp0, iface: ppp0)
Dec 22 13:37:34 localhost NetworkManager[895]:    SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/ppp0, iface: ppp0): no ifupdown configuration found.
Dec 22 13:38:00 localhost dbus[609]: [system] Activating service name='org.freedesktop.PackageKit' (using servicehelper)
Dec 22 13:38:01 localhost AptDaemon: INFO: Initializing daemon
Dec 22 13:38:01 localhost AptDaemon.PackageKit: INFO: Initializing PackageKit compat layer
Dec 22 13:38:01 localhost dbus[609]: [system] Successfully activated service 'org.freedesktop.PackageKit'
Dec 22 13:38:01 localhost AptDaemon.PackageKit: INFO: Initializing PackageKit transaction
Dec 22 13:38:01 localhost AptDaemon.Worker: INFO: Simulating trans: /org/debian/apt/transaction/2de21678372d44db9d30e92b5803ba2d
Dec 22 13:38:01 localhost AptDaemon.Worker: INFO: Processing transaction /org/debian/apt/transaction/2de21678372d44db9d30e92b5803ba2d
Dec 22 13:38:03 localhost AptDaemon.PackageKit: INFO: Get updates()
Dec 22 13:38:04 localhost AptDaemon.Worker: INFO: Finished transaction /org/debian/apt/transaction/2de21678372d44db9d30e92b5803ba2d
Dec 22 13:38:05 localhost pppd[6663]: LCP: timeout sending Config-Requests
Dec 22 13:38:05 localhost pppd[6663]: Connection terminated.
Dec 22 13:38:05 localhost NetworkManager[895]: <warn> VPN plugin failed: 1
Dec 22 13:38:05 localhost NetworkManager[895]:    SCPlugin-Ifupdown: devices removed (path: /sys/devices/virtual/net/ppp0, iface: ppp0)
Dec 22 13:38:05 localhost pppd[6663]: Modem hangup
Dec 22 13:38:05 localhost NetworkManager[895]: <warn> VPN plugin failed: 1
Dec 22 13:38:10 localhost pppd[6663]: Exit.
Dec 22 13:38:10 localhost NetworkManager[895]: <warn> VPN plugin failed: 1
Dec 22 13:38:10 localhost NetworkManager[895]: <info> VPN plugin state changed: stopped (6)
Dec 22 13:38:10 localhost NetworkManager[895]: <info> VPN plugin state change reason: 0
Dec 22 13:38:10 localhost NetworkManager[895]: <warn> error disconnecting VPN: Could not process the request because no VPN connection was active.
Dec 22 13:38:10 localhost NetworkManager[895]: <info> Policy set 'ZyXEL11 1' (wlan0) as default for IPv4 routing and DNS.
Dec 22 13:38:15 localhost NetworkManager[895]: <info> VPN service 'pptp' disappeared
Dec 22 13:38:37 localhost pptp[6669]: nm-pptp-service-6658 warn[open_inetsock:pptp_callmgr.c:329]: connect: Connection timed out
Dec 22 13:38:37 localhost pptp[6669]: nm-pptp-service-6658 fatal[callmgr_main:pptp_callmgr.c:127]: Could not open control connection to 109.188.67.250
Dec 22 13:38:37 localhost pptp[6668]: nm-pptp-service-6658 fatal[open_callmgr:pptp.c:487]: Call manager exited with error 256

С настройками пароля и шифрования всё нормально.
Прошу помощи.