Why Cannot Subnets at the Two Ends of a Normal VPN Connection Access Each Other?

The VPN connection is normal, indicating that the negotiation parameters at both ends of the VPN connection are correct. You need to perform the following operations:

• Verify that routes to the VPN device in your on-premises data center are correctly configured.
• Verify that inter-subnet data exchange is allowed on the VPN device.
• Verify that NAT is not performed on the on-premises subnets that need to access the cloud.
• Verify that mutual access between the public IP addresses of the VPN gateway and customer gateway is permitted.