FortiGate 50b - IPsec to Azure

[kos]

Hello,

We are using firewall FortiGate 50b with a quiet old firmware 3.00-b0752(MR7 Patch 8). By the way it works very good.

But now I need to setup IPsec tunel to Azure RM. Using some manuals I've installed it. But it doesn't work. In log I see only one record, that repeats many times:

notice - negotiate - Initiator: sent 13.91.***.*** (Azure IP) main mode message #1 (OK)

What should I check firstly to troubleshoot this error? Does firmware 3.00-b0752 supported by Azure?

Thank you!