NAT Gateway (CDN)
Network address translation (NAT) is a method used to convert IP addresses. This is relevant because the IP addresses used in a cloud (in a private network) are different to those used in public. This function was originally intended as a means of coping with the increasing scarcity of IPv4 addresses, as it allows multiple virtual machines within a single Virtual Private Cloud (VPC) to be accessed via one public IP address (Elastic IP). This is especially useful in cases where a number of servers in a network perform the same task – they then appear as a single unit to the outside world. Moreover, NAT helps protect virtual servers by hiding the “real IP” (within the VPC) via IP translation, thus preventing attacks from the Internet. The Domain Name Service then translates the IP addresses into plain-text names.
The Open Telekom Cloud has a central NAT gateway that functions as an entry and exit gateway for Internet traffic (via Elastic IP) to and from Elastic Cloud Servers (ECS) in the Open Telekom Cloud. The NAT gateway is compatible with ECS and Bare Metal Servers and supports SNAT (source NAT). Users can select from four gateway types with varying degrees of performance: The maximum number of connections ranges from 10,000 to 1 million, while the number of new connections per second is between 1,000 and 30,000. To use SNAT, the ECS/BMS within a VPC do not need to have their own EIP. The NAT gateway is billed hourly on a “pay-as-you-go” basis.