MAC addresses





Media Access Control (MAC) address. The MAC address is written on the card, and it's physical, so it never changes. It is used between devices, for identification and to transfer packets in the right direction. This works because each packet has a source MAC and a destination MAC, and travels from the source to the destination. In this section, we will study MAC addresses. Each network card, whether it's a Wi-Fi card or a wired card, has a physical, static address, assigned by the card manufacturer. This is the) address. The MAC address is written on the card, and it's physical, so it never changes. It is used between devices, for identification and to transfer packets in the right direction. This works because each packet has a source MAC and a destination MAC, and travels from the source to the destination.

— so it will only be changed for the current session, and once you restart, you will have to change it again. Because the MAC address is static and never changes, it can be used to trace back and identify a device. Also, since devices use MAC addresses to identify each other, we can have some networks that only allow certain MAC addresses to connect to them (by using a whitelist), or that blacklist MAC addresses so that they cannot connect to the network. Changing your MAC address can help you to either connect to a network by being on a whitelist, or to bypass a blacklist. The only way to change the MAC address is to change it in the RAMso it will only be changed for the current session, and once you restart, you will have to change it again.

Now, let's change the MAC address; the procedure is as follows:

1. We're going to use a tool called macchanger . First of all, to get the Wi-Fi card name, just type in iwconfig , and it will show all of the wireless cards. In the following screenshot, eth0 has no wireless extensions, and the same applies to lo ; we can see that wlan0 is the wireless card: We're going to use a tool called. First of all, to get the Wi-Fi card name, just type in, and it will show all of the wireless cards. In the following screenshot,has no wireless extensions, and the same applies to; we can see thatis the wireless card:









2. We are going to disable the wireless card, using the ifconfig wlan0 down command. We are going to disable the wireless card, using thecommand.





3. Now, we're going to change the MAC address, using a tool called macchanger . With these tools, it's always a good idea to look at the help section; just go onto the Terminal and type macchanger --help , and we'll see all of the options that we can use with the tools. You can use --help and --version to show the help and version, --show to show our current MAC address, and -e so that it doesn't change the vendor bytes (the manufacturer of the MAC address). Another method is to try a random vendor MAC of the same kind ( -A is just to set a random vendor here). The -p option will reset the original permanent MAC address, so if we changed our MAC address and we want to use the old one again, we can use -p . The -r option will just give us a random MAC address, and -l will just print the known vendors that we can use. The -m option will help us to pick our own MAC address: Now, we're going to change the MAC address, using a tool called. With these tools, it's always a good idea to look at the help section; just go onto the Terminal and type, and we'll see all of the options that we can use with the tools. You can useandto show the help and version,to show our current MAC address, andso that it doesn't change the vendor bytes (the manufacturer of the MAC address). Another method is to try a random vendor MAC of the same kind (is just to set a random vendor here). Theoption will reset the original permanent MAC address, so if we changed our MAC address and we want to use the old one again, we can use. Theoption will just give us a random MAC address, andwill just print the known vendors that we can use. Theoption will help us to pick our own MAC address:









In case there is a whitelist, we will learn how we can see all connected devices; for example, for your target network, three devices are connected, and the target network only allows three devices to connect. We can just take one of the whitelisted MAC addresses, change it, and use it.

4. To change the MAC address, first we have to disable the wlan0 wireless card by using the ifconfig wlan0 down command. We can use the --random option to set up a random MAC address using macchanger . The command is simply macchanger --random wlan0 . We can use m to specify our own MAC address, if we want. After hitting Enter, we can see that the original MAC address is being changed to 5a:c4:0c:9a:ac:79 : To change the MAC address, first we have to disable thewireless card by using thecommand. We can use theoption to set up a random MAC address using. The command is simply. We can useto specify our own MAC address, if we want. After hitting, we can see that the original MAC address is being changed to









Now, our wireless card is ready, and we've changed its MAC address.

5. Now we need to enable the wireless card again, because we disabled it. So, we'll do the opposite; we're going to use ifconfig wlan0 up . That's it; the card is enabled, and its MAC address has been changed. Let's take a look at it in the following screenshot; if we type in ifconfig wlan0 , we can now see the new MAC address: Now we need to enable the wireless card again, because we disabled it. So, we'll do the opposite; we're going to use. That's it; the card is enabled, and its MAC address has been changed. Let's take a look at it in the following screenshot; if we type in, we can now see the new MAC address:







