• 29 Apr 2024
  • 4 Minutes to read
  • Contributors

    UniFi USG

      Article summary


      This guide will lead you through the procedure to establish a Site-to-Site VPN tunnel between your Harmony SASE network and the UniFi USG environment.

      Breakdown of topics

      1. Pre-requisites
      2. Configuration Steps
      3. Verifying the Setup
      4. Troubleshooting
      5. Support Contacts


      To successfully follow this guide, ensure that:

      1. Have an active Harmony SASE account with an existing network.
      2. Have the Harmony SASE application installed on your devices.
      3. Maintain an operational UniFi USG setup with the necessary administrative privileges.

      Configuration Steps

      If you operate onUniFi Controller 5.13.29 and above, please switch to Classic Mode first.

      Configuring an IPSec tunnel in the Management Platform

      1. Under Network in the Management Platform on the left side, select the network name in which you'd like to set the tunnel.
      2. Locate the desired gateway, and select the three-dotted menu (...).
      3. Select Add Tunnel and then IPSec Site-2-Site Tunnel.

      The following window displays:


      4. In the General Settings section, fill in the following information:

      • Name: Choose whatever name you find suitable for the tunnel.
      • Shared Secret: Enter a string of your own or use Generate.
      • Public IP: Enter the public IP of the UniFi USG device.
      • Remote IP: Enter the public IP of the UniFi USG device.
      • Perimeter 81 Gateway Proposal Subnets: By default, this should be set to
      • Remote Gateway Proposal Subnets: Click Specified Subnets and specify according to your local LAN Subnets.
      1. In the Advanced Settings section, complete the following information:
      • IKE Version:IKEv2 if the Firewall version supports it, IKEv1 otherwise. 
      • IKE Lifetime: 8h
      • Tunnel Lifetime: 8h
      • Dead Peer Detection Delay: 10s
      • Dead Peer Detection Timeout: 30s
      • Encryption (Phase 1): aes256
      • Encryption (Phase 2): aes256
      • Integrity (Phase 1): sha1
      • Integrity (Phase 2): sha1
      • Diffie-Hellman Groups (Phase 1): 21
      • Diffie-Hellman Groups (Phase 1): 21

      Leave the rest of the fields with the default values (as shown in the image below).

      Configuring the tunnel in the UniFi - USG Management Interface

      1. Open the UniFi - USG management interface.
      2. In the left panel, select Networks, then select Create New Network:
      3. Select Site to Site VPN > Manual IPsec and fill in the following information:
      • Enable this Site-to-Site VPN
      • Remote Subnets: Enter the Harmony SASE subnet (by default, it's
      • Peer IP: Enter the public IP of the location server.
      • Local WAN IP: Enter the public IP of the UniFi SCG.
      • Pre-shared key: Enter the Shared Key you chose on the Management Portal. 360009228620ScreenShot2020-02-23at105926copy.png
      1. In the Advanced Options, fill in the following information:
      • Key Exchange Version: IKEv2 if the Firewall version supports it, IKEv1 otherwise.
      • Encryption: AES-256
      • Hash: SHA1
      • DH Group: 21
      • PFS: Enable
      • Dynamic Routing: Disable

      If you need to create a Route-Based IPSEC Site-to-Site between Harmony SASE and your Ubiquiti network, you can check "Enable Dynamic Routing."
      • After doing this, you must add any other Subnet used under "Remote Subnets" and ensure a reverse traffic route is created under Static Routes in the UniFi device for each connected subnet to go back via the Harmony SASE Interface.
      • This would also require you to go back to the Harmony SASE Tunnel you created on the Perimeter81 Admin workspace and change "Perimeter 81 Gateway Proposal Subnets" and "Remote Gateway Proposal Subnets" to Any (
      • You will also need to create separate Static Routing on Harmony SASE. More information can be found in the following article: How to Setup Interconnectivity (Cloud-Agnostic) Between Connected Sites.

      Configuring firewall and static routing

      Next, let's add static routes from the Harmony SASE subnet ( to the local network and from the local network to the Harmony SASE subnet ( to the local network through the VPN tunnel gateway. Also, it's necessary to create firewall rules to allow this traffic.

      1. Go to Routing & Firewall > Static Routes > Create New Route.
      • Choose a name.
      • Enable the route.
      • Enter the Harmony SASE subnet (by default it's in Destination Network.
      • Make sure to choose the interface you created in the previous section.
      1. Create a firewall rule that allows traffic from the Harmony SASE subnet to the LAN Network.

      In case IPS/IDS is enabled on the UniFi:

      To establish a tunnel with the Harmony SASE network in version 7 and above of the UniFi firewall, you must create an exception within your Threat detection system.
      To add a "Threat Management Allow List" entry:

      1. Click on the Firewall & Security tab.
      2. Click Create New Allow List
      3. Select the Site-2-Site network you created earlier (In the step titled "Configuring the tunnel in the UniFi - USG Management Interface")
      4. Save your changes.

      Verifying the Setup

      After following the above steps, your tunnel should be active.
      To verify, go to your Harmony SASE dashboard, locate the tunnel you just created, and check the tunnel status.
      It should indicate that the tunnel is "Up", signifying a successful connection.
      Next, connect to your network using the Harmony SASE agent and attempt to access one of the resources in your environment.


      If you encounter issues during or after the setup, try reviewing your settings to ensure everything matches the instructions. In particular, check the IP addresses and other details you entered during setup. If issues persist, please consult our dedicated support.

      Support Contacts

      If you have any difficulties or questions, don't hesitate to contact Harmony SASE's support team. We offer 24/7 chat support on our website at Perimeter81.com, or you can email us at sase-support@checkpoint.com. We're here to assist you and ensure your VPN tunnel setup is a success.

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