I need to create a "Guest" WLAN network in an existing network. What I need is a Wi-Fi subnet which can only surf the internet and things like that but I won't discuss this here. What I need to know is how can I implement a new "virtual" subnet into an existing network.

Let's say that I have my "main" network which is and I'd like to create a new range of IPs on My router is and my Wi-Fi AP is at; Wi-Fi clients would obviously go on the subnet. I thought that I could make my AP a DHCP server for the subnet and then doing a NETMAP (1:1) from the to the addresses and a virtual interface on my router to make it act as a bridge between the and the net but this is a very very rough solution.

Any ideas? What about VLANs? (I never used one)

  • You may be overcomplicating things. Could you let us know what hardware you are using (router, AP, ...)?
    – Gerben
    Apr 19 '14 at 10:08
  • I use a ZyWall USG 20 as router and a (quite old) Digicom Wi-Fi AP.
    – peperunas
    Apr 19 '14 at 10:16
  • Did any answer help you? if so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.
    – Ron Maupin
    Aug 10 '17 at 3:40

If the ZyWall USG 20 can support multiple virtual interfaces on a specific LAN, you can probably do this like you said where a virtual interface is the gateway for the subnet. However, what's to stop a client from configuring an IP address on and getting whatever the first subnet gets.

My suggestion is that if your AP can put clients on different VLANs depending on the SSID, then that's much better. So SSID1 will be on VLAN 1, and SSID2 will be on VLAN 2. Put a virtual interface of the router on VLAN 1 for and another virtual interface of the router on VLAN 2 for, then you can do whatever you need to control the traffic. I am not sure if the Digicom AP can do that, but that's probably the best option.

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