Managed cloud NAT gateways are convenient, but their pricing model rewards nobody but the cloud provider. Beyond an hourly charge, you pay a per-GB data-processing fee on every byte your workloads send out — and that line grows with every workload you put behind it. Here are practical ways to reduce that spend, the trade-offs of each alternative, and a flat-priced option that removes the per-GB tax entirely.
What a cloud NAT gateway does
A NAT (Network Address Translation) gateway is a managed service that lets resources in a private subnet reach the internet or external services without exposing them to inbound traffic. Your virtual machines talk out securely while staying hidden from the outside. For a deeper walk-through of the mechanics, see How NAT Gateways Work.
From NAT instances to managed gateways
Before managed gateways, teams ran NAT instances — virtual machines configured to forward outbound traffic. They worked, but you owned the OS configuration, the scaling, the patching, and the failure modes. Managed NAT gateways removed that overhead with provider-run scaling and resilience, which is why they became the default.
The convenience came with a pricing model that meters traffic.
The costs: where the money goes
A managed NAT gateway has two cost components:
- An hourly charge for the gateway itself.
- A per-GB data-processing charge on everything that passes through it.
The hourly charge is predictable. The per-GB charge is the one that scales with your business — and it applies whether the traffic was useful or not. For an environment moving a few terabytes of egress a month, the data-processing line routinely dwarfs the hourly cost. The exact rates vary by provider and region, so check current published pricing; the shape of the bill does not change.
Ways to cut NAT spend
Consolidate traffic. Route through a central gateway rather than several, to reduce the hourly component across the environment.
Cut unnecessary egress. Examine your traffic and remove redundant outbound data. Local caching or a CDN for frequently fetched content takes load off the metered path.
Right-size workloads. Over-provisioned instances generate more outbound traffic than they need to. Scaling efficiently reduces what you pay to process.
Turn on monitoring. Logging on the gateway shows you which flows are expensive, so you can target the worst offenders.
These help at the margins. They do not change the fundamental problem: you are billed per gigabyte for address translation.
The alternatives
NAT instances still suit some cases — development environments, or workloads that can tolerate lower resilience:
- They avoid the per-GB data-processing fee, charging only standard egress rates.
- They can be shut down during idle periods to save money.
- They give you full control over configuration.
The catch is that you are back to owning Linux networking, scaling, and availability — the operational overhead managed gateways were created to remove.
A flat-priced NAT replacement: Enforza
Enforza replaces the cloud NAT gateway with a single firewall instance that does secure NAT, egress control, and identity-aware hostname (FQDN) filtering — on flat per-firewall pricing, with no per-GB data-processing tax.
- Flat licensing. One predictable per-firewall line instead of a metered per-GB bill. Forecast it like buying a box, not like reading a utility meter.
- More than NAT. Secure NAT plus egress, ingress and east-west filtering and hostname (SNI/FQDN) rules in one place — see the secure NAT gateway and features pages.
- Runs anywhere. AWS, Azure, GCP — one console across clouds, no per-cloud retraining.
- No exposed management plane. The firewall manages outbound to the Enforza cloud — there is no inbound admin port to expose, unlike a self-managed NAT instance.
Enforza is the way to replace your cloud-native NAT and firewall without taking on either the per-GB tax of the managed service or the maintenance burden of rolling your own.
A note for Azure users
Azure has retired default outbound internet access for virtual machines; the change took effect on 31 March 2026. New VMs no longer get an implicit outbound IP, so you now choose an explicit egress path — a NAT gateway, a public IP, or a firewall instance. That makes the cost of the path you pick a live decision rather than a default you inherited. The trade-offs are covered in Azure default outbound retirement.
Final thoughts
Cloud NAT gateways buy convenience and charge for it by the gigabyte. You can trim that bill with consolidation and caching, drop the data-processing fee by running NAT instances at the cost of operational overhead, or move to a flat-priced firewall instance that removes the per-GB tax and adds real egress control. Knowing where your money actually goes — the hourly charge or the per-GB tax — is the first step to spending less of it.
