Re: [B.A.T.M.A.N.] batman-adv mesh slows down wired clients (bridge-loop-avoidance)

Linus Lüssing
2011-02-24T19:44:14Z

Hi Vinay,

On Thu, Feb 24, 2011 at 12:02:55PM -0500, Vinay Tharigopula wrote:
> Hello..
>
> I succesfully configured a batman-adv mesh to add access points to
> our existing wired lan. I am using Openwrt 10.04 and batman-adv
> 2010.1.0. DHCP and everything works as expected. Any wired or
> wireless client connecting to the network gets an IP from a DHCP
> server hooked into the switch etc etc.
The bridge-loop-avoidance feature has been added in 2011.0.0 and
is not available in 2010.1.0.

If switching to 2011.0.0 helps, don't read any further :).

Could you explain a little more which interfaces you've added to
batman-adv and which interfaces you are bridging with bat0?
(ifconfig, brctl show, batctl if output from one router would be
helpful)

>
> Our Network configuration:
>
> 8 batman-adv routers with a wireless mesh with two or more of the
> routers having a wired connection directly to the switch. In this
> case, the 8 routers decide to pick one of the "plugged in" routers
> as a gateway to avoid bridge loops. This is fine.
>
> I have been running into issues with wired clients however.
>
> When a wired client plugged into the switch tries to contact a wired
> client plugged into the same switch, the packets manage to get lost.
> I believe they are are going through the wireless routers plugged
> into the same switch.
>
> Instead of going like this..
>
> PC 1 ----> switch1 ---> PC 2
>
> they seem to be going like this... (my guess).
>
> PC 1 ---> switch1 ---> wireless router 1 ----(wireless mesh
> link)----> wireless router 2 ----> switch1 ---> PC 2.
Could you please verify with "batctl td" (or tcpdump/wireshark) if
the packets are leaving on the wireless router 1's wifi interface?

>
> I think this is because the translation tables on the bat node are
> announcing that even the wired clients are connected to them.
Could you check with batctl tl and batctl tg if these tables are changing
rapidly? If you do not have any client roaming, then these tables are
expected to stay rather static.

>
> This is causing extreme delays even in wired clients. Any help will
> be appreciated. Should I enable STP in on the switch ports ?
It does not sound like having disabled STP is your problem.

>
> - Vinay
>

Cheers, Linus