Which file contain the mac address for ipv6 on Linux machine?

Linux

On a Linux machine, the MAC address for an interface can be found in the /sys/class/net/<interface>/address file, where <interface> is the name of the network interface (like eth0 or wlan0). Additionally, the MAC address can also be viewed using the ip link show <interface> command. For IPv6 specifically, while the MAC address itself doesn't change, it can be used to generate the Interface Identifier in the IPv6 address format.