Change MAC address

Are you saying they have the same mac? That's unual. Some computer NICs can be changed, but without further info, I haven't any idea about what you've got.

What kind of devices?

In general (plus or minus the discussion in this ng about what happens or how it should be handled when two MAC addresses are the same), every single MAC address should be globally unique.

The mac addresses should be different anyway. What type of devices are they, NICs?

Regards

Bill

However, unique MACs are only required on the local network. One you pass through a router, the original MAC is lost, along with the rest of the original ethernet (or other) frame.

:In general (plus or minus the discussion in this ng about what happens :or how it should be handled when two MAC addresses are the same), :every single MAC address should be globally unique.

Though that's not the underlying definition: the underlying requirement is not -global- uniqueness, but rather uniqueness per segment.

OK, they only have to be unique per segment to make that particular segment work, but in general, they should be globally unique, so any device will work on any segment with any other device. And yeah, there are nits you can pick all day, but I suspect the OP needs to give them (globally) unique addresses.

Hopefully, he can find unique addresses. There are only 281 trillion of them available. ;-)

Maybe we'd better start salvaging the MACs from all the NICs that have been trashed over the years. ;-)

Normally, a NIC will be shipped from the factory with a globally unique MAC address. One exception to this is when you have multiple NICs in a SUN computer. In that case, the default is to have one MAC address for all the NICs in the machine. The idea is that the address is for the computer, not the NIC and that there would be no reason to have more than one NIC connected to an ethernet segment. You can change this default and have a seperate MAC address for each NIC by setting a value into the correct variable in the open boot program.

I'm sorry I cannot share your optimism... After setting the Individual/Group address bit to 0 and the Universally or Locally administered address bit to

(See IEEE Std 802-2001 subclause 9.2 for more details.)

Michael (remove filter from email address)

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