Re: BUG: 2 NICs on same network

[Roland Kuhn]

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Hi!

On Tue, 23 Apr 2002, Frank Louwers wrote:

> Hi,
> 
> We recently stummed across a rather annoying bug when 2 nics are on
> the same network.
> 
> Our situation is this: we have a server with 2 nics, each with a
> different IP on the same network, connected to the same switch. Let's
> assume eth0 has ip 1.2.3.1 and eth1 has 1.2.3.2, with a both with a
> netmask of 255.255.255.0.
> 
> Now the strange thing is that traffic for 1.2.3.2 arrives at eth0 no
> matter what!
> 
This is in perfect agreement with rfc1122, section 3.3.4.2. Linux uses the 
weak ES model, so the interface doesn't matter. There was once a patch 
floating around for 2.4.6 that made the kernel accept only arp coming from 
the 'right' interface. arp_self_only, or something. I have attached it, 
but I have no idea if it still applies/works.

Ciao,
					Roland

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