Expert question

[Michiel]

Dear all,

My situation is as follows;
ISP (Cable Modem) -> Netgear R7800 (Router) -> Linksys LAPAC1200 (AP).
I would like to seperate DNS traffic from the AP through the OpenDNS servers without setting up fixed IP's.
In the R7800 firmware I can't find a suitable option.
Is it possible to attach a fixed DNS address to a physical ethernet port?
Or is it possible to run 2 DHCP server with one giving out IP addresses MAC based and the other one standard?
I would also like to have control over traffic, certain devices can't spend more than a couple Gb's each month (750Gb limit).

Is OpenWRT a better option for all this or do I need a dedicated device?

Thanks in advance.

 

[MichaelCG]

I am not 100% following what you are after here? Are you wanting to give out different DNS servers depending upon the specific client via DHCP?

If yes:
- I'm sure there are certain DHCP servers that can do per device DNS servers...it just may not be common nor simple to find and setup
- otherwise two different subnets may be required to have different DCHP scopes and settings
- you will not be very successful running two DHCP servers on the same broadcast domain...just not how it was intended to work

 

[coxhaus]

DHCP is broadcast traffic so you need separate networks. There is no control on DHCP broadcast traffic. It is first come first serve.

 

[Michiel]

All traffic coming from the AP is coming from my kids. They need some filtering which would happen through the OpenDNS servers and they need limits on the traffic from some devices.
I seem to remember an option somewhere to hand out a specific DNS and limit traffic to devices with specific MAC addresses in a DHCP server.

And let's forget about the 2 DHCP server option.

 

[Trip]

Per @coxhaus's comment, the easiest way to do this is at layer 2. You'd wan to onboard your kids' devices to the network via an SSID created just for them, mapped to a unique VLAN, which can then be given separate DNS and traffic controls, per your requirements.

This shouldn't be a problem on the wireless front, as you have a VLAN-capable AP, but on the router/switch side of things, Netgear's stock firmware is not VLAN-capable, so you'll either need to load DD-WRT or OpenWRT, or replace the R7800 with a VLAN-capable wired router (like a Linksys LRT214, which supports up to 5 VLANs) plus another Linksys AP, running your wifi exclusively from the pair of APs.

The purist in me would point you to the latter method, especially as VLAN functionality would be officially supported and wifi would be maximally efficient, coming from a single, centralized product. If you're not keen on the added cost, though, then I'm sure you could make the R7800 work, provided you were willing to tinker with flashing firmware and a good bit of trial-and-error.