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Public External Gateways

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Updated 1 week ago

What is a Public External Gateway?

A Public External Gateway is the link between your router and Patrii Cloud's public IPv4 network — the network that carries real, Internet-routable IPv4 addresses.

Attaching an external gateway to your router unlocks two things:

  • Outbound access (SNAT) — all VPS behind the router can reach the IPv4 Internet (updates, APIs, package installs) by sharing the router's public address. Direction: VPS → Internet.
  • Floating IP support — the router can translate a public Floating IP to a private VPS address, making the VPS reachable from the Internet. Direction: Internet → VPS.

⚠️ Without an external gateway, a router has no presence on the public network — so neither outbound IPv4 Internet access nor IPv4 Floating IPs are possible.

Why is the External Gateway a paid resource?

Public IPv4 addresses are a scarce and costly resource worldwide — the global supply is exhausted and blocks must be acquired and maintained. Every router connected to the public network reserves capacity on it.

The External Gateway charge covers:

  • Reservation of public IPv4 network capacity for your router
  • The public IPv4 resources and NAT infrastructure that carry your traffic in and out
  • The routing and SNAT service that lets every VPS behind the router reach the Internet

💡 Cost-saving note: A single router with one external gateway can serve many VPS and multiple Floating IPs. You don't pay for a separate gateway per machine — every VPS behind the same router shares it.

Why a Floating IP needs the gateway

The address translation that makes a Floating IP work happens on the router. For the router to perform that translation, it must have a foot on the public network — and that foot is the external gateway.

⚠️ You cannot associate an IPv4 Floating IP to a VPS unless that VPS's router has a Public External Gateway attached. The Floating IP would have nowhere to route to.

In short:

  • External Gateway = the router's door to the Internet
  • Floating IP = a specific public address you assign to a VPS through that door

No door, no address. (Full details in the Floating IPs article.)

Avoiding the IPv4 cost entirely

If your workload can run on IPv6, you don't need a router or an external gateway at all. IPv6 addresses are globally routable without NAT, so a VPS attached to the public6 network is reachable directly and for free. See the IPv6 with public6 article.