Scot L. Harris wrote:
On Fri, 2006-01-06 at 12:49, Doug Coats wrote:
different boards shared the same MAC. So on the network I had 4 NICs
with the same MACs and two of them where on the same subnet.
I figured out how to change the MAC that the eth was reporting in the
ifcfg-eth# file and the traffic issued resolved themselves.
My questions are:
Has anyone seen anything like this before? I thought it was outside
of the networking standards to use the same MAC address on any two
machines in the world. Am I missing something?
Have heard of it before. I forget the manufacturer but there was a
batch of NICs that had similar problem many many years ago. In the past
there was a process to get MAC address blocks assigned to the company
making the NICs. I assume this is still in place. In theory there
should not be duplication of MAC addresses.
Do any of you for see problems using these NICs the way that I am?
Just keep track of what MAC addresses you have set and make sure they
come up that way during reboot.
For IPv4 there should not be any problems since the MAC address should
not be passed outside of your LAN. I don't even think this would cause
any problems with IPv6 addressing.
Doug,
I have seen this as well. Have you upgraded the BIOS es lately? There
is an option to the BIOS updater that must be used to set the MAC
address. I cannot remember what it was, but invoking the update program
with /? will tell you.
IIRC, one of the controller's MAC address is fixed while the other is
set when the BIOS is loaded. I cannot remember which is which, but eth1
on my motherboard has the lower address, so I suspect that it has the
fixed address.
There is a label on the motherboard with the original MAC address of the
non-programmable controller. I would add 1 and use the result for the
programmable MAC address.
Bob...
