Dual WAN Failover with same gateway issue

[ricksense]

Hi everyone,

I was wondering if it is possible to set up a dual WAN failover where both WANs have the same gateway.
This could be the case if you have two modems/routers and two connection lines from the same ISP (or they could be different for that matter), and you put an OPNsense device behind them to better manage and protect your network.

Is it possible in OPnsense? Could there be some problems?
Thanks

[ricksense]

anyone?

[viragomann]

No, this isn't going to work at all.
OPNsense uses routing to detect if an upstream connection is alive and route the traffic to the respective gateway. Routing to different devices requires different IPs, however.

You should be able to configure different local subnets on the routers.

It would also be possible if both have the same though, but then they need different LAN IPs and you can only connect a single WAN of OPNsense to them, means you need also a switch between the devices.

[ricksense]

It would also be possible if both have the same though, but then they need different LAN IPs and you can only connect a single WAN of OPNsense to them, means you need also a switch between the devices.

I don't think that I've understood what you mean above.
Thanks

[viragomann]

To be honest, I'm not sure if that really works.
Best is to have different Subnets on different network interfaces.

[Monviech (Cedrik)]

https://github.com/opnsense/core/issues/6576