Hello Team,
I’ve encountered an issue while setting up an IPSec VPN tunnel between an AWS-hosted Firepower Threat Defense (FTD) firewall (managed by FMC) and an on-site Cisco IR1101 router.
In this setup, the FTD is located behind an AWS Network Load Balancer (NLB). I was able to successfully establish the VPN tunnel; however, I’m facing connectivity issues when trying to ping the tunnel interface IP (e.g., 172.16.32.1) from the Cisco IR1101 router, and vice versa.
Interestingly, when I configure the IPSec VPN without the AWS NLB in the path, everything works as expected and I can ping the tunnel IPs successfully.
Could you please help investigate this issue? Additionally, can anyone confirm whether Cisco officially supports IPSec VPN through an AWS Network Load Balancer?
Any insights or configuration recommendations would be greatly appreciated.
