Проблема с поднятием VPN между двумя Zyxel Ultra

Есть два Ultra.
На одном стоит прошивка ku_ra_draft_2.06.B.4.0-7.bin и у него белый IP. Порт для VPN открыт. Пользователь VPN создан, сервис поднят.
На втором ku_ra_delta_2.05.C.4.0-8.bin - есть желание с него цепляться VPN на второй, для локальных нужд.
После настройки, в логе имею такую проблему:

Код:

Aug 04 20:28:47ndmNetwork::Interface::Base: "PPTP0": interface is up.

Aug 04 20:28:50pptp[1102]Plugin pptp.so loaded.

Aug 04 20:28:50pptp[1102]PPTP plugin version 0.8.3 compiled against pppd 2.4.4-4

Aug 04 20:28:50pptp[1102]pppd 2.4.4-4 started by root, uid 0

Aug 04 20:28:50ndmNetwork::Interface: :pPTP: added host route to 93.100.233.159 via 10.40.16.5.

Aug 04 20:28:50pptp[1104]IP: 93.100.233.159

Aug 04 20:28:50pptp[1104]control connection

Aug 04 20:28:50pptp[1104]unix_sock

Aug 04 20:28:50pptp[1105]enable echo requests (30:3)

Aug 04 20:28:50pptp[1105]Sent control packet type is 1 'Start-Control-Connection-Request'

Aug 04 20:28:50pptp[1105]Received Start Control Connection Reply

Aug 04 20:28:50pptp[1105]Client connection established.

Aug 04 20:28:51pptp[1105]Sent control packet type is 7 'Outgoing-Call-Request'

Aug 04 20:28:51pptp[1105]Received Outgoing Call Reply.

Aug 04 20:28:51pptp[1105]Outgoing call established (call ID 76, peer's call ID 76).

Aug 04 20:28:51ndmkernel: fast vpn ctrl: 9fe9645d, 1

Aug 04 20:28:51pptp[1102]Using interface ppp0

Aug 04 20:28:51pptp[1102]Connect: ppp0 <--> pptp (93.100.233.159)

Aug 04 20:28:54pptp[1102]CHAP authentication succeeded

Aug 04 20:28:54pptp[1102]LCP terminated by peer (MPPE required but peer negotiation failed)

Aug 04 20:28:54pptp[1105]Call disconnect notification received (call id 76)

Aug 04 20:28:54pptp[1105]Result code is 3 'Administrative Shutdown'. Error code is 0, Cause code is 0

Aug 04 20:28:54pptp[1105]Closing connection (call state)

Aug 04 20:28:54ndmkernel: fast vpn ctrl: 9fe9645d, 0

Aug 04 20:28:54pptp[1102]Modem hangup

Aug 04 20:28:54pptp[1102]Connection terminated.

Aug 04 20:28:54pptp[1102]Exit.

Aug 04 20:28:54ndmService: "PPTP0": unexpectedly stopped.

Как лечить?