Creating a home network that uses a hotspot for internet

[Fallen Kell]

So, I have an issue that I am trying to tackle for a friend. Their only internet access comes via wireless hotspot. They would like to setup an internal wireless network so that they can hook up their laptops, wireless printer, tablets, game consoles, etc., and simply have it such that when they are home and turn on their hotspot on their phone(s), that the rest of their network then has access to the internet.

It got me thinking that something like DD-WRT or OpenWRT would let me possibly do this, but I am not 100% certain of the configuration. They have a Linksys WRT3200ACM wireless router, which I loaded up with the latest build of DD-WRT (since I know the stock firmware has no hope to do something like this). My thought is to create a virtual interface on the 2.4GHz band (since most of their devices are compatible), and set it up like any normal network (i.e. DHCP from the router, current secure wireless encryption, possibly setup ACLs (however I think that will be too much for them to maintain), all on it's own subnet, etc...).

Then on the normal 2.4GHz band interface, configure a wireless bridge to the hotspot, and set that as the default route. Thus, whenever the hotspot is on/available, everything would start routing out to the internet, via the wireless/client bridge to the hotspot.

Does this make sense? Does this seem like the right way to do it? I thought about setting up as a wireless repeater, but that entails letting the hotspot be the DHCP server, and as such would require the hotspot to be up and running for anything else to be able to communicate over the internal network, and that is not what they are looking for as they want to be able to print from their laptops/tablets without needing to have the hotspot up and running and/or view video from the latops to the game console without needing to have the hotspot running.

 

[VirtualLarry]

That sounds like you're on the right path.

I did something similar with a D-Link (I think) router, flashed with DD-WRT, had my own home wireless LAN, piggy-backing on another wireless I had available.

Back then, though, it was generally the Atheros builds that let you do client bridge / client mode, AND set up a "virtual interface". I couldn't do that on a Broadcom router build.

Maybe that's change, though, in the last few years, and you can now also set up virtual interfaces on Broadcom routers. (I think that those WRT32000ACM routers are Broadcom?)

 

[ch33zw1z]

Setup ddwrt in client bridge config, plenty of tutorials out there.

Or buy a bridge.

I would go the ddwrt route

 

[Fallen Kell]

Setup ddwrt in client bridge config, plenty of tutorials out there.

Or buy a bridge.

I would go the ddwrt route

I thought about using client bridge, but I was pretty certain that only bridges wired devices. I also debated using a second device as a simple bridge device, but didn't want to make it more complicated that it had to be (they are not very technical... to the point which I had a call once when they couldn't get their computer to turn on, and when I was over the next time and looked at it, it was unplugged...). I wanted it to simply be one device so I could tell them if/when they have problems, simply unplug it and plug it back in (i.e. reboot).

 

[ch33zw1z]

Well, good luck with that hehe, users be like huh? Unplug the thingy from the thingy and count to how many?

 

[Fallen Kell]

Yeah, so I made a stupid mistake. I had at least a large portion of the functionality working (not entirely sure wireless was fully working, but a wired connection was properly getting an IP, DNS, etc., and the router was connected via wireless to my home network (simulating the hotspot), and I could reach the internet. Then as I was reading through all the documentation and Wiki's for DD-WRT, it said I should be using "client" mode and not "client bridge", as "client bridge" was a clutch/hack that should only be used as a last resort.

So, I said, ok, I will give it a shot, clicked to change how the router was connecting to my wireless network to client, and everything breaks.... Can't even ping the router through a wired connection using static IP's on the subnet I setup for the router (or the default out of the box 192.168.1.1). Factory-reset later and now I can't get it to do what I had it previously doing (even though I stepped through the exact same things I did the first time)... Gonna have to look at it some more.

That being said, I previously was able to setup a virtual wireless interface on the 2.4GHz band so that it can both connect to their hotspot and run a wireless network on the same band. The WRT3200ACM uses the marvell chipset, however, the wireless devices are atheros based (ath0, 1, etc.) with the driver supporting making virtual interfaces. I can confirm that it was at least broadcasting the wireless networks before I fubar'ed it all up...

 

[Fallen Kell]

And I have it all configured to work now. I have the virtual interface for the 2.4GHz band with the virtual interface setup as AP mode, and the non-virtual interface in client mode to be the route out to the internet. I tested the 5G and 2.4GHz wireless networks and the wired network to ensure that they all properly DHCP and route over the wireless client connection. Now I just need to take it on over and configure any/all hotspot devices that they use to have the same wireless protocol, SSID, and encryption keys.

A nice bonus for this router is that it has an actual on/off toggle rocker switch. So I can tell them to switch it on/off to reboot instead of unplug the wire.