Configuring an Omada Gateway as a PPTP/L2TP VPN Client to Enable VPN Server as Proxy Gateway for Backend Clients

Application Scenario:

Using the following network topology as an example, we will configure Router B as a PPTP/L2TP VPN Client and connect to the PPTP/L2TP VPN Server (Router A).

Configuration Overview:

1. Configure Router A as PPTP/L2TP VPN Server.
2. Configure Router B as PPTP/L2TP VPN Client.

Case 1: All backend clients want to access the Internet via the VPN Server.

Case 2: Specific backend clients want to access the Internet via the VPN Server, requiring configuration of Policy Routing on Router B (PPTP/L2TP VPN Client) for specific devices.

Configuration Steps:

1. Configure Router A as PPTP/L2TP VPN Server.

NOTE: For detailed configuration instructions, please refer to the following articles:

How to establish an L2TP Server by Omada Gateway in Standalone mode

How to establish a PPTP Server by Omada Gateway in Standalone mode

2. Configure Router B as PPTP/L2TP VPN Client.

Case 1: If you want all the backend clients to access the Internet via the VPN Server, please refer to the following article:

How to set up PPTP & L2TP VPN client with Omada Gateway in standalone mode

Note: A Remote Subnet set to 0.0.0.0/0 will allow all backend clients Internet access via the VPN Server by default.

Case 2: If you want specific backend clients to access the Internet via VPN Server, please refer to the following article before proceeding:

How to set up PPTP & L2TP VPN client with Omada Gateway in standalone mode

After completing the configuration, please refer to the steps below:

1. Configure Policy Routing on Router B (PPTP/L2TP VPN Client) for specific devices.

NOTE: (In this scenario we use L2TP VPN Server and L2TP VPN Client as an example. The configuration is the same for PPTP VPN Server and PPTP VPN Client.)

2. Go to “Preferences → IP Group” to configure corresponding IP group and IP address range settings for the specific devices that will access the Internet via the PPTP/L2TP VPN Server as a Proxy Gateway.

3. Next, go to “Transmission → Routing → Policy Routing” to create a rule for the devices.

In this example we select “test1” under “Source IP”. This would be the IP group name you configured in the previous step.

Then, select “L2TP” next to “WAN“. This will route the relevant traffic of the clients in the IP Group via the L2TP VPN tunnel.

Note: Here we select “IPGROUP_ANY” next to “Destination IP”. This means the routing rule will forward all the traffic of the clients in the selected IP Group.

4. Verification.

(1) By default, without Policy Routing, the devices would access the Internet via their default gateway (e.g., 192.168.10.1). This can be verified using Traceroute via Command Prompt (e.g., “tracert 8.8.8.8”)

(2) With Policy Routing enabled, the devices access the Internet by using the VPN Server 192.168.0.1, as a Proxy Gateway. This too can be verified using Traceroute via Command Prompt (e.g., “tracert 8.8.8.8”)