UniFi - Adopting a USG into an Existing Network


This article describes how to adopt a UniFi Security Gateway (USG) into an existing network, and replacing an already functioning router. With gateway devices having a static LAN IP, the process of adopting a USG can differ from that of a UniFi Access Point (UAP) and a UniFi Switch (USW) in that it may require some initial IP configuration prior to adoption. This article will guide users through said process.

Table of Contents

  1. Plan Deployment
  2. Configure the LAN Network
  3. Change the USG LAN IP Before Adoption
  4. Adopt the USG and Configure the WAN
  5. Related Articles

Plan Deployment

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When deploying into an existing network, the USG will replace the current router or firewall device. The USG's WAN will plug into the Internet connection, and its LAN into the switch for the internal network.

When replacing a current router, the USG will substitute it and take over its IPs.

Do not connect the USG's WAN until after it has been adopted.

If an Internet Service Provider's (ISP) modem is currently acting as the router, there are additional considerations in the modem’s configuration. It is usually best to put the modem into bridge or passthrough mode, so the USG’s WAN obtains the public IP, and the modem’s involvement is limited to bridging. See the modem’s and ISP’s documentation for instructions and options, as these can vary widely. The current router’s LAN subnet and IP will need to change, as it will no longer be connected directly into the LAN network.

Configure the LAN Network

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To configure the IP and other LAN parameters that will be deployed to USG once adopted, launch the UniFi Controller. Once there:

  1. Go to Settings
  2. Select Networks
  3. Click on Edit, under Actions on the far right of the LAN table
  4. Set the IP and DHCP parameters as desired, and click Save

Now the configuration is ready to deploy to the USG. It may be adopted now.

Change the USG LAN IP Before Adoption

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If the controller is on a subnet other than the USG’s default, it is necessary to change the USG’s LAN IP so the controller and USG can communicate. A local UI option is coming for this, but for now it can easily be done via CLI.

1. Connect a computer into the LAN NIC of the USG. It will obtain a 192.168.1.x IP from DHCP.

2. SSH into using username ubnt / password ubnt.

3. For this example, the controller is on, so let's change the USG’s LAN IP to Choose an available IP within the subnet of the local controller.

4. In the SSH session, run the following (for a USG, on a USG Pro replace eth1 with eth0):

set interfaces ethernet eth1 address
delete interfaces ethernet eth1 address

Now the USG’s LAN IP is The SSH session will drop.

5. Plug the USG’s LAN into the network with the controller at

6. Go into the controller and adopt it. Note: Before adopting, make sure you changed the LAN network in the Controller Settings as described above, so it doesn’t revert back to the default controller configuration of

Adopt the USG and Configure the WAN

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In the UniFi Controller, browse to Devices using the left hand side menu.

1. Find the USG and click the Adopt button. It will provision the configuration as currently defined in the controller and reboot. While it’s doing that, configure your WAN interface specifics.

2. In USG’s Properties pane on the right side, go to the Configuration tab, and expand WAN 1. (Click on the USG on the Devices list to make the Properties pane appear). In the Connection Type drop down, pick the appropriate type for your Internet connection. Refer to information provided by your ISP to obtain this information. If using a static IP WAN, make sure to also define two DNS servers here. This is optional for DHCP and PPPoE WANs, as your ISP will likely assign a DNS server, but can be manually specified in that case if desired.

3. After the WAN configuration provisions to the USG, plug its WAN into the Internet connection. For cable and DSL service, it is often required to power cycle the modem after connecting a new gateway device. In those cases, power cycle the modem after plugging in the USG’s WAN.

After the modem boots back up, you should have Internet connectivity from your LAN via the USG. Verify the WAN information in the controller (following step 2 once again).

Related Articles

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Back to Basics - How to Establish a Connection Using SSH

UniFi - How to Setup your Cloud Key and UniFi Access Point (for beginners)

UniFi - Advanced Adoption and Managed By Other UAP

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