There are two ways to deploy CGNAT: as a "one-armed" configuration, also known as "CGNAT on a stick," or as a "routed" configuration.
In the "one-armed" configuration, all traffic will pass through the CGNAT device, including both IPv4 and IPv6 traffic. In contrast, in the "routed" configuration, only IPv4 traffic will pass through the CGNAT device, and IPv6 traffic will bypass it.
When deploying CGNAT in a Dual Stack network, it is important to consider which configuration is best suited to your network's needs and to ensure that your CGNAT solution supports both IPv4 and IPv6 protocols.
The "routed" configuration is generally considered to be the more preferable and cost-effective option for CGNAT deployment in a Dual Stack network. This is because it allows IPv6 traffic to bypass the CGNAT device, reducing the processing load on the device and improving network performance for IPv6 traffic. However, it is important to note that this configuration may not be suitable for all networks, and the "one-armed" configuration may be necessary in some cases.