fiirewall error PPTP VPN

Hello,

We have installed multiple Mikrotik routers on remote locations, which are VPN connected to RHEL linux server with PPTP client. Time to time someone of routers produces this error and generally everything is working fine, except one router today, which disconnect internet every 5 second.

firewall info
dstnat: in:pptp-out1 out:(unknown 0), connection-state:new proto TCP (SYN), 192.168.1.0:55668->192.168.1.42:81, len 52.
I try to change IP address of the router and with new IP address router is working fine for 12 hrs, then the error is back again, but now without disconnecting internet.
We have few dstnat rules in firewall NAT for port forward and problem is only with one rule.
Dst Port 81
To Adresses: 192.168.1.42
To Ports: 81
Maybe some advice what is wrong, I can’t find anything on internet.

192.168.1.0 is server
192.168.1.40 is router

Thank you in advance!

If the 192.168.1.x addresses use a subnet mask of /24 then 192.168.1.0 is not a valid address, so I would expect it to never work.

Also use a better VPN protocol than PPTP, fundamental vulnerabilities have been known for over 10 years making it insecure.

Hi, thanks for your answer. x.x.x.0 is legit IP address and is working in our system as IP of PPTP server perfect for more than 2 years. We don’t need secure VPN, PPTP is in use just to establish virtual private network, no sensitive data is send over, just video.

Regards