Good Morning,
I'm cloning a Sunblade with Solaris 9. I need to make the Nic MACs match. I find two general answers 1. It can't be done, or 2. something like this work:
ifconfig le0 ether aa:1:2:3:4:5
It that all that is required to change a MAC?
Well firstly I would caution you to ensure that they are kept very separate. A common switch or VLAN could panic if it seems to see the same MAC on two ports.
It's been a while since I have done this sort of thing (Solaris 2.6!) where we labelled the NIC with a MAC based on the sub-area-node definition for a VTAM connection to an IBM mainframe. I think we actually set the Token Ring NIC with that and the Ethernet NIC with something else. I think the licence was based on it, so you might need to be careful for that too. I regret that I don't have any Solaris left 
The 'It cannot be done!' is a lie, for some architectures at least. Some lesser Operating Systems can't cope though. I think you have it about right though.
Robin
Why do you find it necessary to spoof a MAC address?
What are you trying to achieve? To clone a Solaris system for production you generally don't need to alter the hardware MAC address because it has no bearing on anything. You might need to change the hostid of the system but not the MAC address.
It has to do with one of the applications. The MAC must match.
You should check whether that is correct. I've heard of licence managers requiring a specific hostid but not a specific MAC.
I think changing the MAC may prove difficult. Who's telling you that the MAC must match???
NOTE: The hostid of a SPARC Solaris system is computed from the MAC address so that might be confusing things. However, if the ISV says the MAC must match then, I guess, it must be so.
Hmm good chance that's why then. I'm just accepting this requirement with the same reasoning.. "It must be so"
So its not as easy as
ifconfig le0 ether aa:1:2:3:4:5
???
I don't see any harm in trying it but I wouldn't expect it to work.
Many licence managers rely on you not being able to change the MAC address on an adapter and, indeed, many network interfaces are built onto the motherboard so tying the application to the machine.
Do you know the name of the licence manager software (if there is one) or does the app simply read the MAC address of the system it's on?
If you are moving your application from one hardware platform to another ie, legitimately, then the ISV should be willing to issue you with the necessary files to port it.
We know how to change the hostid and most license managers use that and not the MAC address. The hostid is computed from the MAC address but we can change the hostid but changing the MAC address could prove difficult.