WiFi failover for wired connection

Hi there,

I run 2 ipq806x routers (Netgear R7800 & Zyxel NBG6817), which are connected to each other via ethernet cable. However, that cable is running outside our house (weather can damage it / someone can cut it) and I would like to have an automatic failover, when the cable connection fails.

About 2 years ago, I ran a wireless WDS between both routers, which worked remarkably fine, which I honestly didn't expect. No connection losses over the course of a few weeks, performance was great, I could stream and even game. So there is definitely no concern in that regard.

I want to set it up in a way, that the WDS / wireless connection always stays established, but all the traffic gets routed over ethernet cable. Once the cable connection fails, I want the device to transparently and seamlessly route over WiFi. Both routers run OpenWRT 19.07.4.

Afaik, the technical term for it is failover / teaming / bonding and I've heard it in context with two identical LAN / WAN ports. But I couldn't find anything like I want to do: bond (failover mode) LAN and WiFi.

It's very likely I'm searching with the wrong technical terms, but I couldn't find a way to accomplish it with OpenWRT. Hope someone can give me a few hints about this.

Thank you for your time!

Cheers,
Tolga

your probably thinking of vrrp / hsrp / carp / etc...

but in this case... I think you'd be better off with rip/ospf/eigrp/etc.

2 Likes

If they belong to different networks, then a routing protocol like ospf (not rip or eigrp) would do.
If they belong to the same network, then stp.

3 Likes

Thank you very much! I've looked into all protocols above and it looks like OSPF / STP seems pretty close to what I want to achieve. I've also added a diagram of my network, in order to make it a bit clearer:

Zyxel NBG6817 serves DHCP, does NAT, firewall etc. and Netgear R7800 pretty much acts like a dumb AP + VLAN switch. The Zyxel is currently set up as 192.168.X.1 and Netgear R7800 as 192.168.X.2. If I understood it correctly, OSPF would require me to connect the R7800's WiFi interface as 192.168.X.3 to the Zyxel? And in case of RSTP aswell, right?

I also want to ask, whether 802.1ax / Link Aggregation / LACP would not be a possibility?

A few thoughts.
You cannot pass vlan tagged frames over wifi. You'll need to have one SSID per vlan.
It seems that you have the same broadcast domain in both locations, therefore your only option is stp.
Link Aggregation will not work here, as you need equal speed links.