General • L2TP site-to-site not working - but client yes

Dear All!

I have a strange problem between two Mikrotik devices. In Site A I have an RB4011, on Site B, there is an hAP AX2. Until now there was an L2TP/IPSEC tunnel between them, but suddenly this tunnel went down and won't be established anymore. The server is Site A, the client is Site B. The usernames, passwords, proposals did not changed, only the software updates was meanwhile - now both devices are running the newest available RouterOS. I tried to create new user, password, did not hepled. Below you can find a screenshot, this can be seen when one site try to connect to the opposite.
I made also a test, I created a L2TP client on Site A and tried to connect to Site B, but no success.
The strange in this strory that a different client (for example a Windows PC, mobile phone) is able to connect to any location, without any problem, the tunnel established without any issues - even with those credentials which are used between the two sites.
Also tried to reboot the devices, renew the IP address on WAN port, this did not helped.

Does anybody has any idea what can be the problem?

Thank you in advance.

Statistics: Posted by magicc12 — Thu Mar 13, 2025 12:30 pm

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