eth0 and eth1 on same subnet using netmask

Hi,

is it possible to setup routing:

eth0 (e.g. ethernet) and eth1 (e.g. WLAN)

on the SAME subnet (e.g. 192.168.3.x) just specifying
a special netmask each?

Thank you for ideas

Martin

Martin Klar <(E-Mail Removed)> wrote:
> is it possible to setup routing:

> eth0 (e.g. ethernet) and eth1 (e.g. WLAN)

> on the SAME subnet (e.g. 192.168.3.x) just specifying
> a special netmask each?

What do you mean by setup routing here? You mean such that this
machine will connect users on the ethernet to users on the WLAN when
all are in the same IP subnet? If so, then I would think that would
be a job for _bridging_ (operating at layer2) rather than _routing_
(operating at layer3 - eg IP).

Even if you sorted-out netmasks to make things happen at IP (layer3)
the decision on what to use as a router is made by the client, not the
router, so each system in the Ethernet would need to be configured to
use your system to reach the IPs in the WLAN and vice versa.
UNLESS... you could run proxy-ARP on your system, then while everyone
on the ethernet and the WLAN think they are in the same subnet, you
"fake them out" by responding to their ARP requests with your MAC
addresses.

Given what you've described thusfar, I think it might be best to
enable and setup bridging on your system.

rick jones
--
web2.0 n, the dot.com reunion tour...
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...

Martin Klar wrote:
> Hi,
>
> is it possible to setup routing:
>
> eth0 (e.g. ethernet) and eth1 (e.g. WLAN)
>
> on the SAME subnet (e.g. 192.168.3.x) just specifying
> a special netmask each?

With a netmask of 255.255.255.128
192.168.3.0/25 and 192.168.3.128/25
are two subnets within 192.168.3.x

and interfaces on one and interfaces on the other
no longer are no longer on the SAME subnet.

Select a different netmask for different granularity.

Martin Klar wrote:
> is it possible to setup routing:
>
> eth0 (e.g. ethernet) and eth1 (e.g. WLAN)
>
> on the SAME subnet (e.g. 192.168.3.x) just specifying
> a special netmask each?

If you mean can two interfaces exist on the same wire with
non-overlapping networks, then yes, although there are very few
instances where you'd want that (i.e., run different networks on the
same wire without using vlans).

If you mean can two interfaces exist on different wires with
non-overlapping networks, then yes, of course. Subnet boundaries do not
have to have masks with lengths that are multiples of 8.

The only requirement is that networks do not overlap.