[Bridge] Bridge Problem: Ping works, nothing else does...

Bainbridge, David D David.D.Bainbridge at team.telstra.com
Tue Apr 10 16:37:49 PDT 2007

Thanks Stephen,
I tried it with the bridge having an IP address and without.

With a little help from one of our IT guys, we deleted all entries in
the iptables and it now works!

Not sure why layer 3 filtering should have an effect on layer 2
forwarding rules but anyway..... 

David Bainbridge

-----Original Message-----
From: Stephen Hemminger [mailto:shemminger at linux-foundation.org] 
Sent: Wednesday, 11 April 2007 3:49 AM
To: Bainbridge, David D
Cc: bridge at lists.linux-foundation.org
Subject: Re: [Bridge] Bridge Problem: Ping works, nothing else does...

On Tue, 10 Apr 2007 14:38:46 +1000
"Bainbridge, David D" <David.D.Bainbridge at team.telstra.com> wrote:

> Hi,
> I'm a newbie to linux to an extent but have a need to set up a linux 
> bridge to do some paclet loss testing using netem.  I have a PC with 
> two NIC cards and Fedora 6.  I have created the bridge using the 
> following commands
> #brctl addbr mybridge
> #brctl addif mybridge eth0
> #brctl addif mybridge eth1
> #brctl mybridge up

I assume you setup IP address for mybridge:
  ifconfig mybridge 192.168.0.X

Check status with:
  brctl showstp mybridge

> Physically I have two IP devices with static IP addresses connected to

> the two NIC cards via cross over cables.  I have tested the NIC cards 
> in a non bridged mode and they work fine as normal NICs.  In bridged 
> mode I can ping the other IP device.  The IP devices are actually 
> realtime audio over IP codec devices and they stream using RTP on UDP
port 5000.
> If I connect the cross over cable directly between the two codec 
> devices the audio is transferred fine, if I put the linux bridge 
> between them I get nothing but I can still ping.....
> A brctl showstp shows the eth0 and eth1 are in forwarding status but 
> nothing is happenig.  Can anyone help.  Both Eth1 and 0 are set to Ip 
> address of
> Thanks
> Regards
> David Bainbridge

What hardware is being used for eth0 and eth1, I assume both are normal
ether devices. They need to support source address spoofing, and
promiscuous mode.

Stephen Hemminger <shemminger at linux-foundation.org>

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