On 13 August 2007, Johnny Hughes johnny@centos.org wrote: <snip>
How can 2 nics from different companies have the same mac address .... I don't think that is possible. each card needs a separate MAC address, at least the way I understand networking.
I agree with Doug and Johnny. My belief is that every NIC in the world is supposed to have a unique MAC address. Although the OP has been using these boards without problems, I suspect there is a defect on the boards.
Lanny Marcus wrote:
On 13 August 2007, Johnny Hughes johnny@centos.org wrote:
<snip> > How can 2 nics from different companies have the same mac address .... > I don't think that is possible. > each card needs a separate MAC address, at least the way I understand > networking.
I agree with Doug and Johnny. My belief is that every NIC in the world is supposed to have a unique MAC address.
Everyone believed that except DECnet which expected all cards in the same machine to have the same MAC. The address should be stored in a ROM and initialized at startup, so it is probably a firmware or driver bug.
Although the OP has been using these boards without problems, I suspect there is a defect on the boards.
Yes, different block ranges are supposed to be assigned to different companies. But, it shouldn't hurt anything unless both are connected to the same subnet which you aren't likely to want.
On 8/15/07, Les Mikesell lesmikesell@gmail.com wrote:
Lanny Marcus wrote:
I agree with Doug and Johnny. My belief is that every NIC in the world is supposed to have a unique MAC address.
Everyone believed that except DECnet which expected all cards in the same machine to have the same MAC.
I guess you haven't worked with Sun systems lately. Although every Sun NIC does have it's own MAC address, by default the system uses one MAC for all of them. I have yet to decide if this is a Good Thing or not....
On 8/15/07, Dave K davek08054@gmail.com wrote:
On 8/15/07, Les Mikesell lesmikesell@gmail.com wrote:
Lanny Marcus wrote:
I agree with Doug and Johnny. My belief is that every NIC in the world is supposed to have a unique MAC address.
Everyone believed that except DECnet which expected all cards in the same machine to have the same MAC.
I guess you haven't worked with Sun systems lately. Although every Sun NIC does have it's own MAC address, by default the system uses one MAC for all of them. I have yet to decide if this is a Good Thing or not....
-- Dave K
It actually makes sense, from a failover point of view. I would suspect that if you connected both of those NICs to the same subnet, it would allow immediate failover if one port were to go bad. That scenario assumes they are both on the same subnet though.
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Brian Mathis -
Dave K -
Lanny Marcus -
Les Mikesell