Here is my setup.

Broadband (ADSL) => 2820 => gigabit network with various WiFi access points around the network.

Would it be possible to add a public WiFi access point (i.e. one with no security) on a different subnet from the main network and only have that able to access the internet?

I don't use the 2820's DHCP server as I have one on my own server - so I would need to use the 2820's DHCP server for the new subnet though, I imagine.

Does this make sense (i.e. is it clear what I am asking) ?
Is it possible?

Many thanks.

M

The 2820 will not allow you to use its DHCP for just one subnet, and you probably can't use your existing DHCP server, either. What I do is to connect a separate (WiFi) router to one of the 2820's ports (you'll need a router with an RJ45 WAN port, not an RJ11 ADSL port), and isolate that port into its own VLAN (on the 2820). You configure the 'public' router in standard gateway mode, on a static external address from the 2820's LAN subnet, and allocate a separate subnet to the LAN side of the public router, enabling its DHCP server.

For example, suppose the Draytek's LAN subnet is 192.168.10.1/24:

1. Connect the WAN port of the public router to a LAN port on the 2820, and put that 2820 port into its own VLAN.
2. Give the external (WAN) side of the public router an IP address of, say, 192.168.10.2, and specify its DNS servers (e.g., use the OpenDNS servers or your ISP's).
3. Set the LAN side subnet of the public router to, say, 192.168.11.1/24 and enable its DHCP server.

Devices behind the public router will be double-natted with this configuration, but that shouldn't matter if you're not port forwarding to the public WAN - I'd be very surprised if you wanted to, anyway.

the above will work and is what most people probably do. the other option is to enable the second subnet on the router and use public ips for routing so your other wireless access point ends up with a public ip that is routed rather than a private ip that is double natted as mentioned.

if you want to get fancier than that, then you have to move up to tag based vlans, routers & waps.

cocospm, many thanks for you suggestion. I'd like to try and implement this solution. Could you please tell me which make and model of the router you daisy chained to the Draytek. As a matter of interest, do you think Edimax BR-6574N will do the job? Thanks.

RayC wrote: cocospm, many thanks for you suggestion. I'd like to try and implement this solution. Could you please tell me which make and model of the router you daisy chained to the Draytek. As a matter of interest, do you think Edimax BR-6574N will do the job? Thanks.

I've used different routers on different networks (I use a Linksys WRT54GS for mine). I'm not familiar with the BR-6574N as such, but I don't see a problem - more or less any router with an RJ45 WAN port should work.

As an update, I had an old vigor 2600+ lying around, so I made a virtual LAN on the 2820, and plugged the 2600 into it, and enabled the dhcp on that.

All works very well.
M