Request from AWS NLB didn't enter vpn tunnel

[Dawei_Ye]

Hi ,

We are deploying a Transit VPC architecture right now.

we tried to publish a service via AWS NLB.

NLB would transfer the request to our Gateway ,and we setup a NAT rule to translate the destination to our internal server.

But we found the gateway did translate the packet but didn't transfer to the internal gw(in transit  VPC).

we tried to capture packets via tcpdump and fw monitor.

10.64.6.4 is NLB's addreess.

in tcpdump records,it seems the traffic sent out via physical interface?

in gw logs ,it didn't enter vpn tunnel but did NAT translation.

Regards

[Dawei_Ye]

Additional:
Running R80.20GA in AWS.