Network Card Strangeness

[Paul Howarth]

Jonathan Allen wrote:
>>Do you have the appropriate aliases for eth1 and eth2 in /etc/modprobe.conf?
>>
>>alias eth1 tulip
>>alias eth2 tulip
> 
> Yes - all four NICs have entries:
> 
>    alias eth0 tulip
>    alias eth1 tulip
>    alias eth2 tulip
>    alias eth3 sk98lin
> 
> Any other ideas why eth1 and eth2 don't load properly ?

What messages appear in /var/log/messages when the tulip module is loaded?

>>The router should have a separate IP address for each interface, in the IP 
>>address range for the segment it is on.
> 
> That sparked a lot of discussion in another place, with people agreeing
> with you and others disagreeing.  While some agree that you are right in
> principle, others say that they have running systems that seem to work
> quite satisfactorily.
> 
> My principle concern is that the machine that is bridging these segments
> needs to be known by only one IP address across the whole LAN and that
> there is only one DNS on the network, and which is not on this machine
> but on the segment that links to the Internet.

In your original email, you said:

   "I have four network cards in an FC2 machine.  This machine is supposed
    to act as a system router between different segments of a LAN, some of
    which is Windows, most of which is Linux, some 10baseT and some 100baseT"

If your machine is to act as a router, you're splitting your LAN into separate 
subnets and your router will need an IP address in each subnet. Now you're 
saying it's a bridge, which is an entirely different thing, effectively 
"glueing" the separate networks into one. You don't need multiple IP addresses 
for a bridge (you don't actually need *any*).

Try http://bridge.sourceforge.net/howto.html for more details on bridging.

Paul.