L2TP/IPSec Server does not accept incoming connections after some time

RouterOS General
1

Hello everybody,
I am running a HAP AC² with ROS 6.46.3 behind a FritzBox 6490Cable.

L2TP/IPSec Server is configured (see configuration) on the HAP router, required ports are forwarded from the FritzBox to the HAP router as well.

Connecting via VPN from outside works for some time for both iOS and Win10 devices (time spans from 1d to 1-2w) but than all of a sudden the installation will not allow any new connections via VPN. The log (as far as I can judge) does not tell anything apart from

phase1 negotiation failed due to time up

messages.

From this point any combination of

  • rebooting HAP router (via ssh)
  • rebooting FritzBox
  • unplug - wait for couple of seconds - re-plug-in HAP router
    brings up VPN service again. The combination differs from incident to incident :frowning:

I even bought a 2nd HAP AC² with no success whatsoever.

Any hint is highly appreciated
mikrotik.txt (10 KB)

2

Just in case somebody stumbles over a similar incidence: I tackled this by simply resetting the router and re-configuring the entire system