This is not an mikrotik issue. Most probably it’s a windows issue. However I haven’t been able to find any helpful information anywhere else. Hopefully someone here has experience with windows vpn disconnecting.
I have an issue with a win7 pc that is used for administration of an security system. It’s supposed to hold a permanent PPTP connection to an mikrotk router working as a vpn server. The problem is that this vpn disconnects every few minutes (between 2 and 30 minutes). The pc has internet connection through a mobile broadband router. The pc is setup without any default route. It only has a route to the mikrotik. (This as a security measure and to make sure it doesn’t consume more data from the monthly quota than strictly needed for the administration). As a consequence of this the pc can be considered to be in a closed network.
After disconnect, it reconnects automatically. (It has a scheduled task that reconnects if connection is down.) In mikrotik log I see that the client does not respond to lcp echo request. Hence I would blame the network connection… This problem started a few weeks ago - when the mobile broadband router was replaced. So the item to blame would be the new broadband router. Except that I put another old w7 pc next to the adminpc and this “new” pc has had 0 disconnects for a week, while the admin pc keeps disconneting every few minutes. This new pc is setup the same way as the adminpc - no default routes, just a static route to the mikrotik.
The new pc has got the .pbk copied from the adminpc. Hence the vpn config should be identical.
Both of these pc’s are old HP elitebook 8440s, so they have identical hardware. The “new” pc got reinstalled with w7sp1 just before it got the task of being a vpn connection tester. It has not had any internet connection, nor updates, since the reinstall. The admin pc was used as a regular workstation with automatic updates enable until 2015ish. I can’t blame any automatic updates as this pc held stable vpn connection before the old mobile broadband router died, and there are years since it got any updates.
In case something was screwed up with the pptp, I set up l2tp/ipsec. And guess what - It also disconnects every few minutes.
So, what could cause the windows pc to stop responding to lcp echo requests from the mikrotik, if the network is OK? Where could I find logs that provides more useful information?