Issue with One-Way Traffic on Site-to-Site VPN Between Draytek and Check Point SMB

[rozkie20]

Hello everyone,

Firmware version: 81.10.10

Manage Locally

We are currently configuring a site-to-site VPN between a DrayTek device (Site A) and a Check Point SMB 1600 (Site B). The tunnel is successfully established, and its status appears as active on both ends.

• From Site A to Site B: We can successfully ping hosts — traffic flows as expected.

• From Site B to Site A: Pings result in connection timeouts, and when reviewing the logs, we observe that the connection is being dropped by the firewall.

We performed a packet capture using fw ctl zdebug and received the following message: "No error – tunnel is not established yet"

Despite the tunnel showing as active, this message continues to appear. We have also rebooted the device, but the issue persists.

I've attached relevant images for reference to help illustrate the scenario more clearly.

Has anyone experienced a similar issue before or could offer guidance on how to resolve this?

[G_W_Albrecht]

https://support.checkpoint.com/results/sk/sk108600

https://community.checkpoint.com/t5/General-Topics/Quick-mode-Received-Notification-from-Peer-invali...