Installing a new device, won't change the existing MAC address on your other card. It'll, it is a single 'emulated' network device. The only thing that can more likely to change your address is a driver update which happened to me many times during the past. Consequently, the operating system and the local router will recognize the machine as a new entity on. MAC addresses can change for a few reasons, but the main ones are replacing a network card or intentionally spoofing your MAC address for privacy. For example, if a network adapter is replaced or upgraded on a computer or mobile device, the new hardware will come with a different MAC address. What is necessary after replacing NIC interfaces of bonding device? Replaced motherboard that has an onboard network interface and need to update the MAC address to bring up network connectivity. A Red Hat subscription provides unlimited access to our knowledgebase, tools, and much more.