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Ticket #1146 (new defect)

Opened 15 years ago

Last modified 15 years ago

Packet loss on bridging

Reported by: Assigned to:
Priority: major Milestone:
Component: madwifi: other Version: v0.9.2.1
Keywords: bridge AP access point bridging Cc:
Patch is attached: 0 Pending:

Description (Last modified by mrenzmann)


I have a wired internet gateway running dhcpd and doing NAT. Now i want another box to be a bridge between the wired gateway and wireless network.

So this is what i do:

wlanconfig ath0 destroy
wlanconfig ath0 create wlandev wifi0 wlanmode ap
iwconfig ath0 essid myAP
(optional) iwconfig ath0 key s:KEY
ifconfig eth1 up
ifconfig ath0 up
brctl addbr br0
brctl addif br0 eth1
brctl addif br0 ath0
ifconfig br0 netmask up

This is what I do. The ip i assign for the bridge will not be given to any other host. I also have done iwpriv ath0 wds 1.

So. Without using WEP key on the AP. Every wireless host gets its IP and is connected (almost) nicely. Ping packet loss is about 90% "only"(to the gateway or internet).

When I apply WEP key it gets weird. All the hosts connect to the network and get their IP addresses. But. Some of them have connection and with ping packet loss about 90%.

Some however have no usable connection and with ping to the internet, very very few replys. Most time out(ie. packetloss ~98%).

I would appreciate any help or ideas. Or at least to tell me where is the fault. In the madwifi driver or bridging(ie. it would work for example with a device with Ralink chip).

Change History

02/09/07 23:48:50 changed by anonymous

Sorry for the informational and formating errors.

I correct: Without WEP, the packet loss is ~10% "only".

02/12/07 11:55:32 changed by mrenzmann

  • description changed.

Blind guess: what is the distance between the client(s) and the AP in this scenario?

02/12/07 13:35:28 changed by anonymous

Minimal. The computer for who the connection was the worst, was actully just about half a meter away from the AP. I do not think a signal too good can have a negative effect. I can try and play with this later though.

02/12/07 13:57:21 changed by mrenzmann

A strong signal indeed can have bad effects, and I saw similar symptoms as those you describe (high packet loss for pings etc). FAQ/SignalTooStrong explains the background.

Please let us know if that helped.

02/20/07 17:28:10 changed by anonymous

Excause me for not looking at the FAQ and considering this problem myself.

I did try to move the host away from the AP and have a weaker signal, but this did not help. There is still backet loss between the host and gateway.

The problem now seems to be only with my laptop(which has Intel 3945ABG wireless card) on Windows. The same laptop using Linux, has good connectivity. Strange.