Port forwarding

Port forwarding allows you to expose applications or services that you host on your network (such as HTTP or FTP) to external Internet users. For example, you might implement port forwarding if you host a multi-player game server on your network, or if you have a device such as a security camera in your home that sends its data to a server on your Fiber network. In these cases, your application uses a specific port, and external devices or users know to connect to it.

When do I need port forwarding or port opening?

Typically, a router protects your network from the outside world by limiting external access to your internal network.

But some devices and programs like IP cameras and online games need a connection from the outside internet that’s unimpeded by a firewall. In most cases, port forwarding (for IPv4) and port opening (for IPv6) are configured automatically between your Wifi devices and your connected devices using Universal Plug and Play (UPnP). 

But you don’t want all your devices to have an open connection, because that’s not secure. The solution is port forwarding. Port forwarding tells a router: When a connection request comes through a specific port (that you specify), send that connection to a specific device (of your choosing). Your other devices will remain unaffected by this rule. 

This article applies if you have a Multi-Gig Router, Wi-Fi 6 Router, or a Network Box. If you have a Google Wifi or Nest Wifi Pro router, please refer to Port forwarding or port opening in the Google Nest Help Center.

Most Network Box customers are eligible to upgrade to a Nest Wifi Pro Router. To learn more, visit the Router upgrade for Network Box customers article.

Setting an external port to an internal port number

You can set port forwarding in the following ways:

• From a single external port number to an identical internal port number.

• From a single external port number to a different internal port number.

• From a range of external port numbers to an identical range of internal port numbers.

Port mapping

The following table provides examples of acceptable and unacceptable port mapping for single ports and ranges of ports.

External port(s)	Internal port(s)	Allowed
80	80	Yes
81	80	Yes
83	8080	Yes
8080-8090	8080-8090	Yes
8080-8090	8090-8100	No, range must be identical

Tip: If you do not see changes taking effect within a few minutes please powercycle your router.

Setting up manual and automatic UPnP port forwarding rules

You can set up manual port forwarding rules on a device-by-device basis using advanced settings for the device. If you have UPnP devices on your network and UPnP port forwarding is enabled, the devices can set up port forwarding rules for themselves. You can set up port forwarding manually, configure UPnP devices to set it up, or use some combination of the two. The two sets of rules can coexist and can be in effect until you replace or delete them or remove the associated devices from your network.

You can have only one port forwarding rule for any given external port. If a port forwarding rule is in effect for a port when you or a UPnP device tries to create a new rule for that port, the Network Box rejects the attempt. (How the conflict is reported is up to the application.) If the attempt is rejected, cancel the current rule and then set up a new rule.

Port forwarding with a DMZ on your network

If a DMZ is set up for your network, port forwarding rules take precedence; that is, the Network Box first looks for a port forwarding rule for an incoming request and forwards the request to the DMZ only if there is no port forwarding rule for the port.

If you remove a device from your network, any port forwarding rules for the device are also removed. You can also individually remove port forwarding rules. If you do not have a DMZ, the Network Box ignores subsequent requests for the formerly forwarded ports. If you have a DMZ, the Network Box sends subsequent requests for those ports to the DMZ.