Provides information to Amazon Web Services about your customer gateway device. The customer gateway device is the appliance at your end of the VPN connection. You must provide the IP address of the customer gateway device’s external interface. The IP address must be static and can be behind a device performing network address translation (NAT).
For devices that use Border Gateway Protocol (BGP), you can also provide the device's BGP Autonomous System Number (ASN). You can use an existing ASN assigned to your network. If you don't have an ASN already, you can use a private ASN. For more information, see Customer gateway options for your Site-to-Site VPN connection in the Amazon Web Services Site-to-Site VPN User Guide.
To create more than one customer gateway with the same VPN type, IP address, and BGP ASN, specify a unique device name for each customer gateway. An identical request returns information about the existing customer gateway; it doesn't create a new customer gateway.