MESH configuration, hardware etc

Hi there,

I am newbie in LEDE/openwrt world. Currently I have 3 TP-Link archer c7 v2. I am trying to build a mesh network. I have run through several sites and tutorials so far, and no luck yet.

What I need is

1 - to connect all three routers via 2.4ghz or 5 ghz
2 - one or more of them might have WAN connection through its wan eth port. In this case, any client (mobile phones, laptops etc) connected to any one of the archers through 2.4 or 5 ghz, should be able to access WAN.

I have built a fw with latest ath driver and batman-adv.

How should I configure my routers? How should be /etc/config/network and wireless files?

I saw at some sites, that wireless chipset should support adhoc mode for batman to run. When I type 'iw phy phy0 info' (or phy0), in the output, adhoc is not listed as one of the supported modes, although "mesh point" is in the list. Is this a build/config mistake on my end or atheros QCA988X chipset doesnt support adhoc mode? Is this important?

and several more questions I have but this much is enough I guess. Any help at all is much appreciated.

thanks in advance

Cihan

You need to build a real mesh or just want to interconnect wirelessly beetween them to not have to wire your place... if it is the 2nd one I could tell you how, it is very easy. I have working wirelessly linked TP-Links in home, work, and two more places in home I have 4 (sometimes more too!)

How did you do it? Do you mind sharing your etc/config/wireless and /etc/config/network files?

Here is how: https://gist.github.com/braian87b/8a524a8ad74a36407a8f481e9d16a5c9

I used that configuration on four places with two and three repeaters... It works very well.

You must design your links accoding to your building because each link probably will couldn't by pass more than two walls because of signal, and you could connect two AP to a same emitting link if it is required too.

@braian87b would you mind explaining a bit what the difference is between a "real mesh" and the second option?

@ovizii Yes... The second option is a configuration that has a Main Router acting as AP (Acces Poiint) and one or more secundary routers acting as Client/station (connected to MainAP) and also emmiting same SSID from the Main AP in order to extend the signal...
Many WiFi devices branded as "WiFi extender" / "WiFi Repeater" do this job actually...

but Real Mesh is a Router that connect to one or another Router dinamically and choices routes for data transfer dinamically, you could set up a fake Mesh using extenders/repeaters, but it is just some routers connected beetween themselves in a static manner.

You could read more about this on the thread: Starting with mesh networks

This is a simplified version of the second option configuration scheme:

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Thanks, I had already read about every mesh related thread over here and all I have to show for it are more questions :slight_smile:

Apparently there are a few real mesh hardware providers out there but then you have to use their hardware/software i.e. open-mesh and ubiquiti and a couple of more afaik.

When it comes to using your own hardware and possibly lede firmware as far as I can gather from the threads I have read there is the option of using 802.11s compatible routers or basically any other router coupled with a protocol like OSLR or B.A.T.M.A.N?
Then, reading quickly over these two, I read B.A.T.M.A.N create a layer 2 network, not sure about OSLR though.

Those two how-tos I linked look like they could be a good start, I'll try and give them a go in the next weeks. I have a few old WRTG54Gs lying around so I guess those are going to be used to fool around and learn about mesh.

Oh, btw. do you also lose half of your bandwidth in a mesh for each hop like I seem to remember you do when using a repeater?

Also, I seem to have read somewhere here on lede that a wireless bridge isn't possible due to some wifi drivers, meaning I can 't have a router running lede firmware act as a client AND AP at the same time and NOT briding to a wired LAN segment?

And last, there are a couple of open mesh providers (not sure what else to call them) which you can join like the freifunk initiative, meaning I can get a compatible router, install their complete freifunk firmware, connect that router to my network and thus extend the freifunk range but what exactly is the point of the packages you can add to the lede firmware with freifunk in their name?

Btw. I found a very good read, a guy detailing his experiments and experiences with mesh: https://www.shadowandy.net/2016/03/building-wireless-mesh-network.htm (its done in chapters, fidn the link to the next chapter at the bottom of each)

i.e. first finding: batman layer2 - oslr layer 3 - not sure what the implications are though for me as an end user.

AFAIK mesh is always done at software level, WiFi specification have things like AP, Station, Ad-hoc, WDS...

WDS from same chipset vendor usually works to make point-to-point Wireless links and LAN from both ends works as they are on the same Ethernet Switch, when WDS can not be used because of incompatibilities then RelayD and
igmpProxy packages needs to be used in order to redirect packets from WiFi<->Ethernet, AP-Isolation feature from some WiFi drivers al also an issue, because that block packets between Ethernet and WiFi too.

I think that Wireless mesh usually use between themselves Ah-hoc and have an additional SSID for clients. Routing is done at software, using some software that does some thing, it modifies routing tables or something like that.

I have many routers but so far never have enough time to build a test enviroment and make mesh testings.

Yes, on the other thread they talk about batman, batman-adv, oslr and 802.11s, that is correct.

Great! please post your findings!

Yes, not half but some around, the problem remains in you may have a router that in test are able to transfer about 3Mb/s, but when you use as Client and AP and same time (without wires) or you put as border node of a mesh network that router will have to use that max capable rate of 3Mb/s to transfer data from other AP/mesh-member to your device connected as client and usually you will have about the half ~1.5Mb/s
But this may be or maybe not this way, since rate is because several things, physical distance, signal, noise, cpu usage because of added encryption and key exchange like WEP/WPA/WPA2 TKIP/AES, etc, etc...
Some people even try to use 2.4Ghz to mesh and 5ghz only to clients, other people adds additional Wireless interfaces using USB-WiFi dongles... some have improved data rate and some have worst than before.

That "second option" using WDS that I posted using gist, it works very well on TP-LINKs with atheros chipset...
On an Linksys WRT54 from...MANY years ago, you will no have same luck, you should go at least to some TL-WR1043ND with 8mb hardware or even a dual band 2.4/5ghz like TL-WDR3600 if you want to have more serious and successful tests

There is many of these... they use some configuration and mesh method (batman, oslr, etc) to give you a preconfigured firmware with the needed software packages and configuration needed, some may need you to configure just the IP, some use DHCP to give you IP configuration then mesh software package takes care of functioning...
In my country for example some years ago someone created Obelisco, it was a OpenWRT fork too, it was preconfigured to allow people with basic knowledge on networking to flash it on their hardware and be part of a multi-node network mesh around the city of Buenos Aires.

Since mesh are a thing to be tested and configured well in order to work properly those people do that, and help other people with those preconfigured firmwares.

LEDE is a fork from OpenWRT, AFAIK freifunk firmware, DD-WRT, Gargoyle, etc etc are all forks from OpenWRT... the thing is that many of OpenWRT main developers wanted change some thing on the OpenWRT form or work, and migrated to LEDE.

You will find to read a lot about it, there is batman and batman-adv... I recommend to try 802.11s (I read some people talk about it and I dont know why it keeped in my mind that is the first thing to try.
but read this page: https://www.shadowandy.net/2016/03/building-wireless-mesh-network.htm/3

I remember MANY years ago, I flashed some Dlink dir-300 router (I think it was my first one) to DD-WRT using some guide from the shadowandy website... :wink:

I haven't made any progress yet but simply wanted to add another interesting ressource to this thread: https://gluon.readthedocs.io/en/v2017.1.x/

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yes, for mesh-beginners its very hard to find a working config to start with. even for "normal/experienced sysadmins", because there are very many differences to "normal" networks.

Please start with existing mesh firmware! There are very many mesh communities worldwide, using and developing Openwrt/LEDE, sometimes with hundreds of mesh-nodes in many cities.

Depending on your needs it might be hard to find the nicest mesh-firmware, but you could test some of them. (libremesh, freifunk-gluon, freifunk-meshkit, ..)

http://freifunk.net
http://libremesh.net
http://battlemesh.org
http://ninux.org

@freifunkufo - thanks for the input but what has always confused me, with these projects you linked, will I be taking part in their ope mesh networks or be able to roll my own?