How to change the MAC address of NIC?

You can't. The MAC adress is hardcoded in every NIC. You would have to replace the IC where this data is stored. Why do you want to do this?

Not exactly,you can change it, I did this before but not in 3c509b.
We need to test our self made switcher.

unless you have got a ARC net card, the MAC Address is assigned when the card is made. it is inpossible to change it.
where did you get 3c509b from?? what is that? the model mumber or the maker??

3c509 from 3com, EhernetLink III, it is a old model.
Not only ARC, I test NIC from Xircom, it
also can be changed

Much easier just to swap cards.

Serial number is guarenteed unique by vendor. Where are you going to get a replacement without cannabilizing another card? Instead of unsoldering the large surface mount IC's and attempting to resolder them on another card, don't you think it'ld be easier just to change the entire card?

There is no way for *software* to change the address as it is burned in PROM.

M

BTW - give points to RBW, his answer was correct.

Our switcher is a distubed system, calling singaling is routed by MAC address, my NIC in switch side is easy to config MAC address as we need, but
pc as a management console's mac address can not be changed. We use mac
address as each cancentrator's ID, due to the complex of system softare, if I
change my PC MAC address, i need not to modify the software in main controller,
that's the reason.
who's RBW, I can't find his answer.

i think they mean rbr.

It's the first answer you rejected...

MAC addresses should be transparent to the system. The only spot that it should matter is when you're doing workstation login restrictions and you need to limit an account to a specific machine (like limiting the BACKUP account to the machine that has the tape drive installed...)

Are you *sure* that your NIC is "switch" configurable? I've *NEVER* seen a NIC where you could set the MAC address like this. RAM address - Yes. DMA, IRQ, connector type - yes, yes, yes. But in all the years I've been doing LAN's (about 20) I've NEVER, EVER seen a NIC with a MAC that you could dial in.

What software in the "main controller" are you having to adjust for MAC address? The LAN switch fabric usually learns automatically. I think you may have something else confused with MAC address. What kind of NIC do you have and what is the model and brand of concentrator?

M

Here is hardware zone, right? It is very
normal in embedded software developing to config everthing from MAC address to frame buffer size, why you can't understand?
Don't let switch confusing you, in that side I can config everything on all network layer, my question is if I can change MAC address in PC side, it will be convenient to me, in fact, my Xircom
NIC's MAC can be changed, and it works fine, but it's a PCMCIA type NIC, can't work on my Destop, so I ask this question, I feel it is a normal question, why all you feel it strang, what's the matter?

The question is closed!

We decide to make a change on switch side, so I close this question.
Since at least jhance  know that it is possible, I give points to him.
Thanks for all comments.