Hi,
On Tue, Oct 16, 2018 at 05:00:37PM -0600, Grant Taylor wrote:
> On 10/16/2018 04:31 PM, Leroy Tennison wrote:
> >(1.2.3.4 is an arbitrary replacement but doesn't affect the basic
> >issue) What is causing this? The systems in question have only
> >one interface per subnet but both systems have multiple NICs which
> >are on the same subnets. What I mean is this: on both systems
> >NIC1 connects to subnet 1, NIC2 to subnet 2 and so on for five
> >NICs and different subnets. The subnets do have different IP
> >ranges (no overlap). 10.222.109.3 does happen to be on the same
> >system as 1.2.3.4 but it doesn't have the same mac address and it
> >is a physical interface.
>
> I can't tell for sure. Are the NICs connected to the same L2
> network segment / broadcast domain?
>
> This almost sounds as if NIC1 is responding to ARP requests for NIC{2..5}.
Linux may do that...
> >Address HWType HWAddress Flags Mask Iface
> >10.222.109.3 ether bc:30:5b:a6:c4:bf C eth9
> >1.2.3.4 ether bc:30:5b:a6:c4:bf C eth9
>
> Unfortunately this doesn't clearly indicate if the NICs are using
> the same L2 network segment / broadcast domain or not.
...especially if the NICs are in different broadcast domains (VLANs).
I am not saying that is the case here, just that it might be the case.
That would be an instance of the "weak host model" problem (see RFC 1122,
section 3.3.4.2, "Weak ES Model"). The problem is primarily that some
expectations about network separation are not fulfilled by the end-system.
Thanks,
Erik
--
It's impossible to learn very much by simply sitting in a lecture,
or even by simply doing problems that are assigned.
-- Richard P. Feynman
