2 IPs of same subnet and one gateway problem

Hello!

I have a problem with my Network Configuration in RedHat 9.0!

I have 2 NICs (in case one of them fails or the cabling is not okay...).
They have IPs like 123.123.123.1 AND 123.123.123.2, so they are in the
same subnet. The Gateway for both is 123.123.123.254.

Now I setup Redhat with just one of the cards and everything works fine.
Now I add the second card (BTW a 3COM 3c59x) and load the appropriate
driver. This works well. Now I create a
/etc/sysconfig/network-script/ifcfg-eth1
with nearly the same settings as ifcfg-eth0 (IP-addr. and interface
changed of course).

As soon as I restart the network, just ONE of the NICs is active. The
other one just is not there. The one NIC responds to both IPs.

Then I did it manually:
/etc/rc.d/init.d/network stop
(checked ifconfig... no network up, okay lets go on)

ifconfig eth0 123.123.123.1 up
ifconfig eth1 123.123.123.2 up
route add default gw 123.123.123.254

And: I get the same results as above. Just one NIC responds to both IPs.
Its not always the same. It seems to the NIC which is activeted first.

I crawled through several google search results and got to know that
there are known problems with two IPs in the same subnet. But most of
the articles are due to kernel 2.2.

So do you know what I am missing or where I am going wrong?

Thanks in advance

Steve Holdoway wrote:
> will bonding support help???
>

No, because I need the two different IPs.

GB

Performance issues.

What you are seeing is normal routing behavior. Because standard routing is
based only on the destination and not on bandwidth or any other
considerations, as far as the route table is concerned the second NIC adds
no benefit and it will never be used. The Advanced Routing Howto
(http://lartc.org/howto/) has instructions on how to accomplish fancier
things with the route table, including load balancing over 2 NICs in the
same subnet. This will still not give you any slick auto-failover
capabilities, but it will allow you to make use of both NICs.

--

wcardwell at nc dot rr dot com


"G. Berg" <(E-Mail Removed)> wrote in message
news:bfrqq4$hpn5l$(E-Mail Removed)...
> Performance issues.
>