is it possible to change mac address ..?

According to this article : https://support.apple.com/en-in/HT202068

MAC address authentication or filtering

Restricts access to a Wi-Fi router to devices with specific MAC (Media Access Control) addresses.

Set to: Disabled

When enabled, this feature allows a user to configure a list of MAC addresses for the Wi-Fi router, and restrict access to devices with addresses that are on the list. Devices with MAC addresses not on the list will fail to associate with the Wi-Fi network. MAC addresses can be changed easily, so don't rely on them to prevent unauthorized access to the network.

You must always use : WPA2 personal AES ( advanced encryption standard ) , in the network settings .Read this article .

no the MAC address is a hardware key for the network equipment

like phones has IMEI, but if you have problems with the MAC address of the ethernet card then your wifi has another nr and any other netcards usb connected you added would again have another address

If you really mean 'MAC' address, then no.

If you really mean the Mac's network address then

Apple Menu > System Preferences... > Network

is the place to look. In typical cases you want to let your router provide the IP address 'Using DHCP'.

C.

First question, why?

Second, have you googled/researched how to do this?

Third, if you have to ask, do you really need to do it?

Also, what do you think it will accomplish by changing your Mac address?

If it's a privacy thing with your ISP/public places, changing the Mac won't do anything, your computer and browsing history are much more identifiable than a Mac address.

Even the hostname of the computer would give it away - Khanna's MacBook Air - is much easier way to identify you than by a Mac address.

Get Adblock/Disconnect to block the trackers on the web, relax, and live a little!

I am not sure why you would need to do so for normal use but have a look at https://github.com/feross/SpoofMAC

This is available for Macs as well as other operating systems.

You might also want to see http://feross.org/spoofmac/

According to the following link, it is possible to Spoof it --

http://osxdaily.com/2008/01/17/how-to-spoof-your-mac-address-in-mac-os-x/

Yes the tool I linked to can do this for any network interface. You specify which interface you want it to do it for. See the instructions on https://github.com/feross/SpoofMAC