Mesh based internet access on event location using WR841 routers possible?

Installing and Using OpenWrt Network and Wireless Configuration
1

Hi everyone,

i have a handful of WR841 routers that i want to use to provide internet access to guests on an event location.

Ideally i do not want to route ethernet cables across the venue. Upstream internet connection is only available in one spot of the location from which i can't cover the entire area with a single access point.

Initially i thought i could set them up in a 802.11s mesh according to this page: https://openwrt.org/docs/guide-user/network/wifi/mesh/80211s, but then i read somewhere that most of the client devices would not be able to connect to the same network in lack of 802.11s support.

Can this be done with these routers, considering they have only one physical wifi interface each?

Thanks in advance!

Edit: auth/encryption is not mandatory

2

Yes you can set up two interfaces on the same radio, one mesh and one AP.

Performance will not be that great since the same radio channel is being shared by everything, but it can work. Dual band routers with users on one band (and spread out over different channels) and the mesh on the other band would be considerably better.

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3

Cool, thanks for your quick response, @mk24!

So, something like this should work, though performance could be poor?

config wifi-device 'radio0'
        option type 'mac80211'
        option channel '11'
        option hwmode '11g'
        option path 'platform/qca953x_wmac'
        option disabled '0'
        option country 'DE'

config wifi-iface 'mesh'
        option network 'mesh'
        option device 'radio0'
        option mode 'mesh'
        option mesh_id 'your-mesh-name'
        option encryption 'psk2/aes'
        option key 'your-secret-password'

config wifi-iface 'ap'
        option device 'radio0'
        option mode 'ap'
        option ssid 'Guest Access'
        option encryption 'psk2'
        option key 'gimmeinternets'
4

You'll need routing on top of the mesh, as 802.11s doesn't provide AP-client routing, only that of mesh participants. B.A.T.M.A.N. and OLSR are two popular ways of providing that kind of routing.

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5

Leave encryption off of the mesh. You would need the larger wpad to support that, and that is a considerable problem with 4 MB flash.

The basic 802.11s includes the HWMP mesh routing, it is suitable for small meshes. Usually you will see option mesh_routing 0 included to turn HWMP off so the 802.11s radio is only a radio layer for BATMAN. But that is not necessary for a simple setup.

You need to specify option network lan in both the AP and the mesh to bridge them into the LAN. In /etc/config/network, put option stp 1 in the lan configuration so that it will be OK to connect the nodes with cable and not have a loop.

Again this is a very basic setup to get something going for proof of concept where security is not an issue.

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6

Okay thanks for your hints @mk24 and @jeff. I will try to get something up and running and will surely be back with some questions.

I managed to fit wpad-mesh-wolfssl onto it, dropping ppp and luci.

Just to make sure i understood you correctly: I can try it without BATMAN for a small mesh, correct?