Re: [SLUG] Cannot get Quad port NIC interfaces to ping eachother

[Sam Lawrance <boris@xxxxxxxxxxxxxxx>]

On 06/10/2007, at 7:39 PM, Minh Van Le wrote:

> > What's the physical configuration of the network?  What path do you
>
> It sort of looks like this,
>
>
>    @ @ @ @ @ @
>   @  Internet  @
>    @ @ @ @ @ @
>         |
>         |
> +--------------------+
> | 4 port ADSL Router |
> +--------------------+
>     |
>     |
>     |
>     |
>     +------------------------------+
>                                    |
>                                    |
>     ****************              <RTL-8139C>    eth0 (192.168.1.80)
>    | Red Hat Server |   <--->      |
>     ****************              <4 port NIC>   eth1, eth2, eth3,  
> eth4
>                                    |  |  |  |   (192.168.1.81,  
> 192.168.1.82
>                                    |  |  |  |    192.168.1.83,  
> 192.168.1.84)
>   +--------------------------------+  |  |  |
>   |            +----------------------+  |  |
>   |            |           +-------------+  |
>   |            |           |                |
>   |            |           |                |
>  +--+        +--+       =======       ==========
>  |pc|        |pc|       [ Hub ]       [ Switch ]
>  +--+        +--+       =======       ==========
> /____\      /____\
>
>
> and every node on the network is 192.168.1/24.
>
> Which I thought was a simplier thing until sometime in future I  
> decide to do
> stuff like 192.168.2/24, 192.168.3/24 etc.
>
> But now people are saying I got to subnet the current  
> 192.168.1.1-254 range
> to get my set up above to work.

Yeah.  Probably the ping is going out one interface and based on your  
diagram above, obviously not coming back.

> > expecting the ping to take between eg. eth1 and eth2?
>
> Because the netmask was 192.168.1.0/255.255.255.0 for all my  
> interfaces I
> was expecting the 4 port NIC to act like a switch or hub and
> automatically/intuitively(?)/logically route the ping from eth1->eth2
> correctly.

I don't know how to do it on linux, but you might be able to  
accomplish this by enabling bridging between those interfaces.