[LEDE-DEV] Routing two interfaces on same subnet

[Tobias Welz]

Bridging in client mode is not supported by most devices.
That's why you need a "pseudo bridge" with relayd here:
https://wiki.openwrt.org/doc/recipes/relayclient

On 05.07.2016 23:14, Baptiste Clenet wrote:
> Ok.
> I've got a router with one ethernet port and wifi in STA mode. The
> user which is going to use the router will be able to connect this
> router to internet router either by ethernet or wifi.
> So if he plugs ethernet and decide to connect his router by wifi also,
> ethernet and wifi will be on same network (same subnet).
> Is it clearer?
> Currently, when I start my board, I've got this config even if
> ethernet is unplugged (wifi STA connects automatically):
> root at eisox:/# ip route
> default via 192.168.0.50 dev eth0  proto static
> 192.168.0.0/24 dev eth0  proto kernel  scope link  src 192.168.0.85
> 192.168.0.0/24 dev apcli0  proto kernel  scope link  src 192.168.0.80
>
> Then I can't ping my router because of the route on eth0
> May I use a bridge in this set up?
>
>
> 2016-07-05 20:26 GMT+02:00 Tobias Welz <tw at wiznet.eu>:
>> I think we need to know more about your setup, and what you want to achieve.
>> Let's say we have LAN and WAN interfaces as ethernet ports, and also WIFI.
>>
>> Should the WIFI be in AP or in STA mode?
>> Shall wifi be bridged to LAN or to the WAN interface?
>>
>>
>> -------- Original Message --------
>> Subject: Re: [LEDE-DEV] Routing two interfaces on same subnet
>> From: Baptiste Clenet <bapclenet at gmail.com>
>> To: Tobias Welz <tw at wiznet.eu>
>> Cc: lede-dev at lists.infradead.org
>> Date: 5.7.2016 19:33:02
>>> Wifi and ethernet are in client mode.
>>> pseudo bridge with relayd? Can you describe a bit?
>>>
>>> 2016-07-05 19:24 GMT+02:00 Tobias Welz <tw at wiznet.eu>:
>>>> Hi,
>>>> it's just a little problem if you are in in client mode, then you need a
>>>> pseudo bridge with relayd.
>>>> If you use AP mode then you can just bridge LAN and WIFI together, which
>>>> is
>>>> the default anyway. A factory default will bring you to this setting,
>>>> turn
>>>> on wifi and you are done.
>>>> Regards Tobias
>>>>
>>>> -------- Original Message --------
>>>> Subject: Re: [LEDE-DEV] Routing two interfaces on same subnet
>>>> From: Baptiste Clenet <bapclenet at gmail.com>
>>>> To: Tobias Welz <tw at wiznet.eu>
>>>> Cc: lede-dev at lists.infradead.org
>>>> Date: 5.7.2016 19:15:42
>>>>> Hi Tobias,
>>>>> I see, I tried to bridge them, but I got a problem, I'll try again.
>>>>> Isn't it a problem if both interfaces are connected to same network in a
>>>>> bridge?
>>>>>
>>>>> 2016-07-05 19:04 GMT+02:00 Tobias Welz <tw at wiznet.eu>:
>>>>>> Hello,
>>>>>> for me it looks a bit strange, why not put both interfaces together on
>>>>>> Layer
>>>>>> 2 - so bridge them together - which is the default anyway? It looks
>>>>>> very
>>>>>> strange to me, to split that stuff on layer 3 with the same subnet,
>>>>>> which
>>>>>> now need a lot of hacking to bring it to work again, which i personally
>>>>>> would like to avoid in a production environment.
>>>>>> For me it looks like a "wrong" approach - what is the special need to
>>>>>> doing
>>>>>> it in this way?
>>>>>> What is the problem with using a bridge over these two interfaces which
>>>>>> should just run out of the box?
>>>>>> Regards Tobias
>>>>>>
>>>>>>
>>>>>> -------- Original Message --------
>>>>>> Subject: [LEDE-DEV] Routing two interfaces on same subnet
>>>>>> From: Baptiste Clenet <bapclenet at gmail.com>
>>>>>> To: lede-dev at lists.infradead.org
>>>>>> Date: 4.7.2016 10:14:26
>>>>>>> Hi,
>>>>>>>
>>>>>>> On my board, I've got a wifi and an ethernet interfaces on the same
>>>>>>> subnet (192.168.0.0/24). Problem is if ethernet cable is unplugged I
>>>>>>> can't use wifi anymore, see
>>>>>>>
>>>>>>> root at eisox:/# ip route
>>>>>>> default via 192.168.0.50 dev eth0  proto static
>>>>>>> 192.168.0.0/24 dev eth0  proto kernel  scope link  src 192.168.0.85
>>>>>>> 192.168.0.0/24 dev apcli0  proto kernel  scope link  src 192.168.0.80
>>>>>>> Here, ethernet is unplugged and wifi connected to other router so I
>>>>>>> can't use the wifi (ping failed in both direction).
>>>>>>>
>>>>>>> If I delete eth route, it works.
>>>>>>> root at eisox:/# ip route del 192.168.0.0/24 dev eth0
>>>>>>> root at eisox:/# ip route
>>>>>>> default via 192.168.0.50 dev eth0  proto static
>>>>>>> 192.168.0.0/24 dev apcli0  proto kernel  scope link  src 192.168.0.80
>>>>>>> root at eisox:/#
>>>>>>>
>>>>>>> How can I can solve the problem?
>>>>>>> I won't know the status of Wifi and Ethernet so I would like that both
>>>>>>> can work if they are plugged.
>>>>>>>
>>>>>>> Or how to disable one interface is the other one is connected (like if
>>>>>>> ethernet is plugged, allow only ethernet to work, if it is unplugged,
>>>>>>> allow only wifi)
>>>>>>>
>>>>>>> Cheers,
>>>>>>>
>>>
>
>