Hyperscale firewall Carrier Grade NAT (CGN) features can be used to accelerate dynamic SNAT resource management for IPv4 and NAT64 traffic. Using carrier grade NAT features, FortiOS is capable of managing SNAT resources for complex networks containing large numbers of devices with private IPv4 addresses. Hyperscale CGN uses an enhanced implementation of FortiOS IP Pools to apply these CGN resource management features to traffic as it passes through the FortiGate.
For information about FortiOS IP pools, see Dynamic SNAT.
Start a hyperscale firewall carrier grade NAT configuration by creating one or more CGN resource allocation IP pools. These IP pools are variations on an overload IP pool that define how the firewall manages source addresses and source ports. Then you create a hyperscale firewall policy and add the CGN resource allocation IP pools to the firewall policy.
If you add multiple CGN resource allocation IP pools to a hyperscale firewall policy, the IP pools must all have the same CGN mode (none, overload, single port allocation, or fixed-allocation) and their IP ranges must not overlap.
Instead of adding multiple IP pools to a hyperscale firewall policy, you can create a CGN IP pool group and add multiple CGN IP pools to the group. Then add the CGN IP pool group to the firewall policy. All of the CGN IP pools in a CGN IP pool group must have the same CGN mode and their IP ranges must not overlap.