Connecting a Tomato Router with an existing Wifi Network

I recently moved and therefore had to get a new contract with my ISP. Unfortunately, it as not possible to get the Ethernet modem (yet) and simply hook it to my beloved Netgear WNR3500L v2 powered by TomatoUSB. Instead, the provider shipped a Connect Box, which is very convenient to install for basic use, but does not allow you to define anything more complex than port forwarding. The previous wifi router did have the option to act as a simple bridge, but the new model does not come with this option. Fortunately, the Tomato firmware is very flexible and allows connect as a client into the existing network and provide connectivity to Ethernet ports and also virtual wireless networks.

Setting up the Client Mode

The good thing with this approach is that the primary router I got from my ISP, does not require any modifications or changes in the settings, the ISP Router remains in its original configuration. In this article, the ISP router is denoted as primary router. All modifications are made at the Tomato USB router, which is denoted as secondary router.

Change the IP address of the Tomato Router

First of all, the secondary router requires to have a different IP than the primary router. Make sure that you are connected via Ethernet cable to the secondary router and login using its original IP address, which is most likely Change the IP to in the Basic Network Settings. Turn off DHCP, because the primay router  has an active DHCP server. Of course you can also use the secondary router as DHCP server or use static IPs for all devices. The screenshot below shows the network settings.

Network settingsReboot the secondary router and login again using the new IP address Open the same page again and set the gateway and DNS address to the IP of primary router, as depicted above.

Connect the Secondary Router as Wireless Client with the Primary Router

Remain on the Basic Networking page at the secondary router and set the Wireless Interface as Wireless Ethernet Bridge. This way, the secondary router creates a bridge to the primary router and allows clients connected to the Ethernet ports with the Internet. Enter the SSID of the primary router and provide the password. If you do not know the SSID by heart, you can use the Wireless Survey in the Tools menu. The screenshot below depicts the settings.

Wireless Ethernet Bridge

The Routing

The last step ensures that the routing of the traffic works. Change the mode of the secondary device from Gateway to router and save the settings. The Advanced Routing menu should now look somilar as shown below.


Virtual Wireless Networking

In the last optional step, you can create additional wifi networks from the secondary router which are accessible for other clients. This can be useful if you need to change the SSID on the primary router or are too lazy to change a lot of settings of your smart TV and other devices which still are looking for the old SSID. Open the Virtual Wireless page in the Advanced menu. You will see the connection with the primary router there and you can add additional networks by adding new virtual interfaces. Make sure that the mode of the wireless network is Access Point .  This way you can create additional wifi networks and separate the devices into different zones.

Sources: Youtube

6 thoughts on “Connecting a Tomato Router with an existing Wifi Network

  1. Hello Stefan,

    Very interesting article. I’m having difficulty with my set. I recently upgraded to a Hitron cable modem and am trying to setup my previous Cisco wireless router as an access point. This secondary router will be connected by wire to the primary and I expect to have devices connecting to the secondary in both wired and wireless modes.

    Do you know what changes I would need to make to your configuration to operate it in this manner? Any help you could provide would be awesome.

  2. Great guide Stefan, thank you!

    Changing the routing mode of the secondary device from Gateway to Router was the step I was missing. Once I did that I could get internet access again.


  3. Great work. I’ve one question anyway. Is it possible to do port forwarding using only the secondary router without doing any change on the first ?


  4. I’m a noob in network administration !

    So I tried to activate DMZ in secondary router with IP of the primary, and I tried the opposite. None of them seems to work. But when all DMZ are disabled, if I put a port forwarding rule in the primary router it works, I can reach my local web service from the internet.

    The goal is to keep the entire setup on the secondary router which is not my ISP provided router.

  5. Nice article except you are not using Wireless Client mode, you are using Wireless bridge mode which is different.
    Read here
    and if still confused read here
    though DD-WRT and Tomato work slightly differently.

    It also doesn’t work on a lot of newer routers.

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