[lug] physical/logical network interfaces

[Hugh Brown]

On Tue, 22 Mar 2005, Zan Lynx wrote:

> On Tue, 2005-03-22 at 13:01 -0700, Hugh Brown wrote:
> >
> > Still nothing that would suggest why it wants to have one interface serve
> > for both.
> >
> > I'll have to see what I can dig up in /proc land, per Ralf's suggestion.
> >
> > Hugh
>
> In Linux Land, IP addresses belong to the _machine_, not the interface.
> This means that any interface can pick up packets for any configured IP
> address.  Usually this only happens when the interface is in promiscuous
> mode or if the NIC supports multiple MAC addresses.
>
> I believe the proc settings to allow or prevent this is rp_filter and
> arp_filter.  A handy file to read
> is /usr/src/linux/Documentation/networking/ip-sysctl.txt if you have the
> kernel source on the system.
>
> I think it's funny that you're having this problem.  The reason I know
> about these files is that I had to figure out how to allow it for my
> laptop so that the wireless and wired interfaces could work
> interchangeably.
> --
> Zan Lynx <zlynx at acm.org>
>

Thanks Zan (et al).  This answers the question, I believe.  I can't test
it because it is a production box and losing the interface would be a bad
thing.

Thanks for the help.

Hugh