[LEDE-DEV] Routing two interfaces on same subnet

[Ben Greear]

On 07/04/2016 02:53 PM, Baptiste Jonglez wrote:
> On Mon, Jul 04, 2016 at 10:54:27PM +0200, Baptiste Clenet wrote:
>> Hi Wang,
>> Thank for your answer. May you explain how to do that?
>> I think this should work.
>
> The general idea would be:
>
>    default via 192.168.0.1 dev wlan0  src 192.168.0.12  metric 300
>    default via 192.168.1.1 dev eth0   src 192.168.1.42  metric 200
>
> where the route with the lowest metric is used.  If it disappears, the
> remaining route is used instead.
>
> You should be able to do that on LEDE/OpenWRT, see the metric option here:
>
>    https://wiki.openwrt.org/doc/uci/network#ipv4_routes
>
> The problem is that, in your case, it probably won't work, because:
>
> 1) you mentioned that the route doesn't go away when the interface goes
>     down (which might or might not be a bug)
>
> 2) if both gateways are in the same subnet, chances are you're screwed up
>     anyway, because the kernel will only do ARP on one of your interface,
>     for both routes.  I'd be interested to know if this is not the case.

arp-filter can fix #2.

Thanks,
Ben

-- 
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc  http://www.candelatech.com