Re: Need some helps

On Mon, 10 Oct 2005 10:30:05 -0400
"Hai Wang" <[email protected]> wrote:

> Hello,
> 
>       I have some questions regarding how to bridge VLANs and LAN, I
> have the following scenarios and configuration, but it dos not seem
> to work, please shed some light on it. Thanks!
> 
> I have a Linux box which has 2 GNIC (Eth0 and Eth1) and one ATM card
> 
> 1.) Scenario I
> 
> Packets<------->Eth0<--->Eth1.x(VLANs)<--->Internet
> 
> #vconfig       add eth1   1
> #brctl addbr   br0
> #brctl addif   br0  eth0
> #brctl addif   br0  eth1.1
> #ifconfig      br0 up
> 

This should add a tag with VID=1 in one direction (left to right), and
strip the tag in the other direction.  You may need to "ifconfig
eth1.1 up" too!

Also, note that VID=1 may confuse some third-party switches which are
upstream of your linux-based vlan bridge.  You'd be safer using some
other VID.


> 2. Scenario II
> 
> Host 1(10.10.10.x)--->Eth0<--------->Eth1<---->Host 2 (11.11.11.X)
> 
> #brctl addbr br0
> #brctl addif   br0  eth0
> #brctl addif   br0  eth1
> #ifconfig      br0 up
> 
> I can ping if and only if Host 1 and Host 2 are in the same domain,
> say 10.10.10.X. I believe that bridge should be able to bridge
> traffics between different network domains, but how?
> 

No.  Bridges just extend a broadcast domain.  Every IP stack on that
broadcast domain needs to be on the same subnet.

Also, I can't see what Scenario II has to do with 802.1q vlans....


> Any help is much appreciated!
> 
> Hai
> 
> 

Regards,

Alex