Connection Tracking

RouterOS Beginner Basics
1

Good Day!
My english is bad, My skill in RouterOS is low, so I’ll write as simple as possible.
I have two Mikrotiks RB2011 (MT1 and MT2), located in different towns.
I want to connect two LAN’s with Mikrotik by L2TP.
I create L2TP server, and L2TP client.
MT1 have two Ethernet connections and one Dyn IP from L2TP-server:

  1. WAN
  2. LAN 192.168.1.0/24, MT1’s IP 192.168.1.254 (LAN1)
    DynIP 10.10.16.1/24

MT2 have also two Ethernet connections and one dyn IP from L2TP-client

  1. WAN
  2. LAN 192.168.6.0/24, MT2’s IP 192.168.6.254 (LAN6)
    DynIP 10.10.16.2/24

Then I add needed routes on both routers:

On MT1 route to 192.168.6.0/24 via 10.10.16.2
On MT2 route to 192.168.1.0/24 via 10.10.16.1

I add needed firewall rules to passthrow RDP traffic from LAN6 to LAN1 (tcp:3389) and Netbios (tcp:445)
Seems to work.
But I have a problem(
RPD connections often breaks.
User connect to RDP-server, login, work. 5-10-20-30 minutes past - then RDP connection freeze and then reconnection.
While RDP connections break, ping is normal, no losts.
I was in pain all this week, serfing google, but nothing help me(
And yesterday, I find button “Tracking” on TAB “Connection” in Firewall window.
It was set as AUTO. I set them to NO, and seems like breaks go out.

So, my questions to RouterOS’es gurus… can this setting breaks connections? Can I calm down?

Thanks alot.