If your Mac is set up to connect to a Wi-Fi network, it can analyze the connection for issues that affect its performance, including its connection to the Internet. If you've followed the steps to connect your Mac to a Wi-Fi network, but the connection to your network or the Internet isn't reliable, the steps in this article might help. How to find the MAC address in Mac OS. Go to Utilities (Finder Utilities OR command + shift + u) and start the Terminal app. Type this in the Terminal: networksetup -listallhardwareports You will be a list of all the network interfaces with their MAC addresses (Ethernet Address). An example output is this. I borrowed hp 2570p from my friend and successfully installed macOSx network cart worked perfect. After that I bought the same hp 2570p with the same 82579LM Gigabit network card but now during installation network card doesn't work and after reboot. How it can be the same laptop the same.

  • What is a network card?
  • What is the role of a network card?
  • Preparing data
  • The role of the identifier
  • Other network card functions
  • Sending and controlling data
  • Network card configuration settings


What is a network card?


A network card (also called a Network Adapter or Network Interface Card, or NIC for short) acts as the interface between a computer and a network cable. The purpose of the network card is to prepare, send, and control data on the network.

A network card usually has two indicator lights (LEDs):

  • The green LED shows that the card is receiving electricity;
  • The orange (10 Mb/s) or red (100 Mb/s) LED indicates network activity (sending or receiving data). To prepare data to be sent the network card uses a transceiver, which transforms parallel data into serial data. Each cart has a unique address, called a MAC address, assigned by the card's manufacturer, which lets it be uniquely identified among all the network cards in the world.

Network cards have settings which can be configured. Among them are hardware interrupts (IRQ), the I/O address and the memory address (DMA).

To ensure that the computer and network are compatible, the card must be suitable for the computer's data bus architecture, and have the appropriate type of socket for the cable. Each card is designed to work with a certain kind of cable. Some cards include multiple interface connectors (which can be configured using jumpers, DIP switches, or software). The most commonly used are RJ-45 connectors.
Note: Certain proprietary network topologies which use twisted pair cables employ RJ-11 connectors. These topologies are sometimes called 'pre-10BaseT '.

Finally, to ensure that the computer and network are compatible, the card must by compatible with the computer's internal structure (data bus architecture) and have a connector suitable for the kind of cabling used.

What is the role of a network card?


A network card is the physical interface between the computer and cable. It converts the data sent by the computer into a form which can be used by the network cable, transfers that data to another computer and controls the dataflow between the computer and cable. It also translates the data coming from the cable into bytes so that the computer's CPU can read it. This is why a network card is an expansion card inserted into an expansion slot.

Preparing data


The paths taken by data moving with a computer are called 'buses'. Multiple side-by-side paths force data to move in parallel, and not in series (one after another).

  • The first buses transported 8 bits at a time.
  • IBM's PC/AT computer introduced the first 16-bit buses.
  • Today, most buses are 32-bit. However, data travels on cables in series (only one channel), moving in only one direction. The computer can send OR receive data, but cannot do both at once. For this reason, the network card restructures a group of data arriving in parallel into a serial (1-bit) data stream.

To do so, the digital signals are transformed into electrical or optical signals which can travel over network cables. The device that translates them is called the transceiver.

The role of the identifier


Network

Network Card For Mac

  • The card converts data and notifies the rest of the network of its address, so that it can be told apart from the other network cards.
  • MAC addresses: Defined by the IEEE (Institute of Electrical and Electronics Engineer), which assigns ranges of addresses to each manufacturer of network cards.
  • They are inscribed on the cards' chips, and as a result, each card has a unique MAC address on the network.

Other network card functions


The computer and the card must communicate so that data can travel between them. For this reason, the computer assigns part of its memory to cards that include DMA (Direct Access Memory).

The interface card indicates that another computer is requesting data from that computer.
The computer's bus transfers the data from the computer memory to the network card.

If the data is moving too fast for the adapter to process, they are placed in the card's buffer memory (RAM), where they are temporarily stored while the data is being sent and received.

Sending and controlling data


Before the sending network card transmits its data, it interacts electronically with the receiving card to resolve the following issues:

  • Maximum size of data blocks that will be sent
  • Amount of data to send before confirmation
  • Intervals of time between partial data transmissions
  • Waiting period before sending confirmation
  • Volume of data that each card may build up before releasing it to its CPU
  • Data transmission speed If a more recent, advanced card communicates with a slower one, they still have to share the same transmission speed. Some cards have circuits for adjusting themselves to the transfer speeds of a slower card.

Both cards must accept and adjust to the other card's settings before data can be sent and received.

Network Card For Windows 10

Network card configuration settings


Network adapters have configuration options: Among others:

  • Interruption (IRQ): In most cases, network cards use IRQ 3 and 5. IRQ 5 is recommended (whenever available) and most cards use it as the default setting.
  • Input/Output (I/O) base address: Each device must have a different address for the corresponding port.
  • Memory address: This designates a RAM location in the computer. The network card uses this slot as a buffer for data entering and leaving. This setting is sometimes called the RAM Start Address. In general, a network card's memory address is D8000. The last 0 is left out on some network cards. You have to be careful not to select an address already being used by another device. It should, however, be noted that some network cards have no configurable memory address because they don't use the machine's RAM addresses.
  • The transceiver

MacNote: The card can be configured using software. The settings have to match the placement of the jumpers or the DIP (Dual Inline Package) switches found on the network card. These settings are provided with the card's documentation. Many recent cards use PnP (Plug and Play). This means that the card does not need to be manually configured, but sometimes can cause hardware conflicts; when this happens, it is helpful to disable the PnP option and configure the card 'by hand.' Our network card has at least two addresses or identificators, the IP address we all know which can be dynamic and the physical address, the mac address which is unique for each device, it is the hardware address. Changing our mac address may be useful to avoid leaving logs with our real address on another computer or router. Changing the mac address may be useful to clone other mac addresses forcing them to get disconnected from a network and connecting again, useful to sniff the password when reinserted.

In this brief tutorial you’ll learn how to check your mac address and how to edit it randomly or for a specific replacement mac address.

For this tutorial I will work on the network card enp2s0, replace this network card for yours (e.g eth0, wlan0, etc.)

Network Cards For Mac

To check your mac address just execute:

We can see on the enp2s0 network card the mac address is d0:17:c2:12:3c:cd while the wlp3s0 wifi card mac address is a2:58:a6:6a:29:04. Mac addresses 12 digits, 6 fields of 2 characters and letters separated by “:” like XX:XX:XX:XX:XX:XX.

The first 6 characters and numbers belong to the device manufacturer, in my case d0:17:c2 belongs to ASUS. The last 12 digits are the ID number for the hardware and it is unique.

First of all, to edit our network card mac address we need to disable our network card, the mac can not be changed while the card is being used. To disable our network card run:

Then, to edit our mac address type:

Then enable the network card back by typing:

If you need to edit our mac frequently maybe is convenient to use a program called macchanger, to install it on Debian or Ubuntu systems run:


During the installation you’ll be asked if macchanger should start when a networking device is enabled, here you can decide whatever you want, changing your mac address by default shouldn’t create problems unless you have your router configured to accept specific mac addresses.

Select any of the options and press enter to finish.

After macchanger is installed we can also check our mac address by typing

As you can see it matches with the mac address exposed using ifconfig.

Here Macchanger shows the current mac, the real hardware’s mac (Permanent MAC) and the new one if you assign it.To change your mac address fast for a random address simply run:

Make sure you run macchanger as root and that the network device is down. If you get an error when running this command then run:

To disable your network card, after it type “ifconfig” again and you’ll see your network card wont show up.

Then run macchanger -r again.

Change network card mac address

If we want to assign our card a specific address we can execute:

For example

If we set our card up and run an ifconfig we’ll see our new mac address.

After editing our mac address we need to enable the network card back, for this run::

Network Card For Mac Pro

Now we can see our system also displays the new mac address 32:ce:cb:3c:63:cd.

Mac Network Connection

Firewalls and IDS can contain policies whitelisting and banning specific mac addresses. Manipulating our network cards’ physical address is a great step to avoid leaving traces in logs and increase your privacy by masking your device or to bypass security obstacles when pentesting a network, the most common use as said at the starting is when we want to crack a wifi access dissociating a connected device with the aircrack suite by cloning it’s mac address.

Network Card For Mac

I hope you found this tutorial on macchanger useful, keep following LinuxHint for more tips and updates on Linux.