topic GRE Tunnel log DROP: Received a cleartext packet within an encrypted connection. in General Topics

GRE Tunnel log DROP: Received a cleartext packet within an encrypted connection.

staboi — Tue, 24 Jan 2023 10:42:40 GMT

Hi experts,

I created tunnel between MikroTik to Check Point using GRE Tunnel. It shows that the traffic was dropped with "Received a cleartext packet within an encrypted connection" warning. 1 thing that I noticed is that I can't set tunnel ID in mikrotik as what checkpoint could. What exactly is the cause of this issue and how to troubleshoot this? Any help would be greatly appreciated.

Thank you.

Re: GRE Tunnel log DROP: Received a cleartext packet within an encrypted connection.

G_W_Albrecht — Tue, 24 Jan 2023 10:52:32 GMT

Maybe this helps ? sk169794: GRE Configuration Guide

Re: GRE Tunnel log DROP: Received a cleartext packet within an encrypted connection.

Timothy_Hall — Tue, 24 Jan 2023 12:46:01 GMT

If you are receiving that message, the firewall believes based on the src/dst IP addresses of the packet that it should have been sent encrypted from a VPN peer but it wasn't. You will need to adjust your VPN domains such that the firewall does not believe that traffic should have arrived in a VPN tunnel. The inspection of the packet and determination whether it should have been encrypted happens before the packet is passed to the Gaia OS between inspection points i-I, so it can't even reach the GRE handling in the Gaia OS.