High latency using brctl, eventual timeout.

Question

When using brctl, my latency on the notebook that is doing the bridging becomes horribly slow. Eventually, I cannot get the notebook to connect to anything, even the routers admin panel, or pinging the router.

The scenario is I have an 802.11b router upstairs, an 802.11b card in my notebook, and an eth port in my notebook. I am setting up the link using the following:

gary@fluffy:~$ sudo ifconfig ath0 0.0.0.0
gary@fluffy:~$ sudo ifconfig eth0 0.0.0.0
gary@fluffy:~$ sudo su
root@fluffy:/home/gary# brctl addbr br0
root@fluffy:/home/gary# brctl addif br0 ath0
root@fluffy:/home/gary# brctl addif br0 eth0
root@fluffy:/home/gary# dhclient br0
Internet Systems Consortium DHCP Client V3.1.1
Copyright 2004-2008 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

wifi0: unknown hardware address type 801
wifi0: unknown hardware address type 801
Listening on LPF/br0/<removed>
Sending on   LPF/br0/<removed>
Sending on   Socket/fallback
DHCPDISCOVER on br0 to 255.255.255.255 port 67 interval 6
DHCPDISCOVER on br0 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on br0 to 255.255.255.255 port 67 interval 7
DHCPOFFER of 192.168.0.6 from 192.168.0.1
DHCPREQUEST of 192.168.0.6 on br0 to 255.255.255.255 port 67
DHCPACK of 192.168.0.6 from 192.168.0.1
 * Reloading /etc/samba/smb.conf smbd only
   ...done.
bound to 192.168.0.6 -- renewal in 39109 seconds.
root@fluffy:/home/gary# ifconfig br0 up

This works great at first. The eth0 port allows the other device to connect, and the notebook can still connect to the web just fine. But after 4 hours or so, the notebook times out to EVERYTHING. It's happened every time I've tried it so far, 4 total.

I can understand the latency, as it has to accept a ton of extra work to connect the device on eth0 to the network, but WHY does it keep timing out like this? And why does it only do it after 4 hours? Google has turned up NOTHING, which is disappointing.

Answer 1

how's your network topology? is your upstairs router on the same ethernet LAN and your wifi card is also accessing that router? then you have a cycle in your network, no good.

check the amount of traffic going by your bridge (i like iftop, but simply checking the counters in ifconfig can help) if you find usage suddenly soar, that's your problem.