I'm considering replacing or reducing our managed NAT Gateway usage with FCK-NAT to lower networking costs. Has anyone operated it in production, particularly with several terabytes of monthly outbound traffic? I'd like to understand its reliability, maintenance requirements, failure recovery, and recommended high-availability setup across Availability Zones.
3 Answers
I’ve been running it for about six months and haven’t experienced any problems. So far it has been reliable in production.
I’ve run FCK-NAT in several production clusters for around 18 months, and it has been remarkably trouble-free. The savings become significant when moving multiple terabytes of traffic each month. The main trade-off is that you’re responsible for maintaining the instances, and an outage can interrupt outbound connectivity until recovery. Make sure automated recovery, startup configuration, monitoring, and replacement procedures are well tested.
Would running two instances in separate Availability Zones behind an Auto Scaling Group be enough for resilience? We currently process more than 5 TB of traffic.
I deploy one FCK-NAT instance in each of the three Availability Zones we use, so every zone has an independent path for outbound traffic. It has worked well enough that it rarely needs attention. For a smaller organization, this setup can be a practical way to reduce costs, provided you’re comfortable managing the instances and capacity yourself.
That sounds like a solid approach for our traffic level. We’re handling over 5 TB, so using separate instances per zone may be safer than relying on a single shared instance.

Good to hear. Did you have to handle any unexpected failovers, upgrades, or performance issues during that period?