how to forward packets on two NICs - Networking
This is a discussion on how to forward packets on two NICs - Networking ; Hi all
I have to build a sniffer on our voip network so as to monitor what is going
wrong on it (bad communications quality) and my problem is that I can't
mirror the traffic because the switchs are not ...
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how to forward packets on two NICs
Hi all
I have to build a sniffer on our voip network so as to monitor what is going
wrong on it (bad communications quality) and my problem is that I can't
mirror the traffic because the switchs are not manageable. All the IP phones
are on the same subnet and the IPBX is the gateway.
Because I am not familiar with Voip protocols, I don't know really how all
this stuff is working... And I am looking for a solution which won't need to
change the IP topology... if it's possible.
I had the idea to configure the sniffer with two NIC and to forward all the
packets from one NIC to the other one, like a switch with 2 ports if you
want (I know that this is not a very good way to act but has I have said, I
would like to avoid changing the IP of the IPBX).
Do you think it is a solution ? If yes, do you know how to configure that ?
if no, do you see another solution ?
I have found a package call parprouted which allows to forward the ARP
requests, now I guess that I just have to find the same thing for IP packets
as there is no dhcp/bootp protocols here...
thanks in advance
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Re: how to forward packets on two NICs
On Mon, 03 Nov 2008 16:03:26 +0100, Julien Simbola wrote:
> I had the idea to configure the sniffer with two NIC and to forward all
> the packets from one NIC to the other one, like a switch with 2 ports if
> you want (I know that this is not a very good way to act but has I have
> said, I would like to avoid changing the IP of the IPBX).
This is called a bridge...
Google for linux bridge howto..!
--
Regards/mvh Joachim Mæland
If everything seems under control, you're just not going fast enough.
-Mario Andretti
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Re: how to forward packets on two NICs
I have been able to set this up, thanks to you Joachim
For those who are interested in a solution, it's pretty simple
Here is the way to proceed (using 2.6 kernel):
apt-get install ebtables
apt-get install bridge-utils
brctl addr br0
brctl addif br0 eth0
brctl addif br0 eth1
ifconfig br0 up
thank you
cheers
"Joachim Mæland" wrote in message
news:hqh3u5-329.ln1@snila.linuxgutta.no...
> On Mon, 03 Nov 2008 16:03:26 +0100, Julien Simbola wrote:
>
>> I had the idea to configure the sniffer with two NIC and to forward all
>> the packets from one NIC to the other one, like a switch with 2 ports if
>> you want (I know that this is not a very good way to act but has I have
>> said, I would like to avoid changing the IP of the IPBX).
>
> This is called a bridge...
>
> Google for linux bridge howto..!
>
>
> --
> Regards/mvh Joachim Mæland
>
> If everything seems under control, you're just not going fast enough.
> -Mario Andretti
>
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Re: how to forward packets on two NICs
Hello,
Julien Simbola a écrit :
>
> Here is the way to proceed (using 2.6 kernel):
>
> apt-get install ebtables
> apt-get install bridge-utils
Ebtables is not required to set up a simple bridge. It is required only
to do layer 2 filtering/mangling on the bridge. Bridge-utils works with
a 2.4 kernel too.
