The password of your macOS user account is also known as your login password. It's the password that you use to log in to your Mac and make certain changes, such as installing software.

Change your password

If you know your password and can use it to log in to your account, you can change your password in Users & Groups preferences:

1. Choose System Preferences from the Apple menu, then click Users & Groups.
2. Select your user name from the list of users.
3. Click the Change Password button, then follow the onscreen instructions.

Reset your password

Device info application is the most comprehensive, powerful and fancy app that provide you with all the information you need to know about your phone, system and hardware with the most attractive and beautiful user interface (using Material Design). FEATURES: Dashboard. Device IDs information (IMEI, SIM Serial No., Android Device ID, IP Address, WiFi Mac Address, etc). System (phone) general. Payments are based on the received device matching the description you provided when your estimate was made. Apple reserves the right to refuse or limit the quantity of any device for any reason. In the Apple Store: Offer only available on presentation of a valid, government-issued photo ID (local law may require saving this information).

If you don't remember your password, or it isn't working, you might be able to reset it using one of the methods described below. But first try these simpler solutions:

IOS (formerly iPhone OS) is a mobile operating system created and developed by Apple Inc. Exclusively for its hardware.It is the operating system that powers many of the company's mobile devices, including the iPhone and iPod Touch; it also powered the iPad until the introduction of iPadOS, a derivative of iOS, in 2019.It is the world's second-most widely installed mobile operating system. I need a script which, given a USB path, returns me the vendor ID and product ID of the device. I need this information standalone ( I don't have to interact with the device). – Sceik Feb 26 '14 at 13:51. Vendor id and product id of a mounted usb device in Mac OS cocoa.

• Make sure that you're typing the correct uppercase or lowercase characters. If your keyboard has Caps Lock turned on, the password field shows a Caps Lock symbol .
• If the password field shows a question mark, click it to display a password hint that might help you to remember.
• Try to log in without a password. If that works, you can then add a password by following the steps to change your password.
• Try to log in with the Apple ID password that you use for iCloud. If you just changed that password and the new password isn't working, try the old password first. If that works, you should be able to use the new password from then on.

Reset using your Apple ID

In some macOS versions, you can use your Apple ID to reset your login password. At the login screen, keep entering a password until you see a message saying that you can reset your password using Apple ID. If you don't see the message after three attempts, your account isn't set up to allow resetting with Apple ID.

1. Click next to the Apple ID message, then follow the onscreen instructions to enter your Apple ID and create a new password. You'll be asked to restart when done.
2. Log in with your new password.
3. Determine whether to create a new login keychain.

Reset using another admin account

If you know the name and password of an admin account on your Mac, you can use that account to reset the password.

1. Log in with the name and password of the other admin account.
2. Choose System Preferences from the Apple menu, then click Users & Groups.
3. Click , then enter the admin name and password again.
4. Select your user name from the list of users.
5. Click the Reset Password button, then follow the onscreen instructions to create a new password:
   
6. Choose Log Out from the Apple menu.
7. Log in to your account using your new password.
8. Determine whether to create a new login keychain.

Reset using the Reset Password assistant (FileVault must be on)

If FileVault is turned on, you might be able to reset your password using the Reset Password assistant:

1. Wait up to a minute at the login screen, until you see a message saying that you can use the power button on your Mac to shut down and start up again in Recovery OS. If you don't see this message, FileVault isn't on.
2. Press and hold the power button until your Mac turns off.
3. Press the power button again to turn on your Mac.
4. When the Reset Password window appears, follow the onscreen instructions to create a new password.
   If you need to connect to Wi-Fi, move your pointer to the top of the screen and use the Wi-Fi menu to connect. To exit without resetting your password, choose Apple menu > Restart.
   
5. When done, click Restart.
6. If you were able to reset your password with the Reset Password assistant, log in to your account using your new password.
7. Determine whether to create a new login keychain.

Reset using your Recovery Key (FileVault must be on)

If FileVault is turned on and you have a FileVault Recovery Key, you can use that key to reset your password.

1. At the login screen, keep entering a password until you see a message saying that you can reset your password using your Recovery Key. If you don't see the message after three attempts, FileVault isn't on.
   
2. Click next to the message. The password field changes to a Recovery Key field.
3. Enter your Recovery Key. Use uppercase characters, and include the hyphens.
4. Follow the onscreen instructions to create a new password, then click Reset Password when done.
5. Determine whether to create a new login keychain.

If you can't log in with your new password after restarting your Mac, take these additional steps:

1. Restart again, then immediately hold down Command-R or one of the other macOS Recovery key combinations until you see the Apple logo or a spinning globe.
2. When you see the macOS Utilities window, choose Utilities > Terminal from the menu bar.
3. In the Terminal window, type resetpassword, then press Return to open the Reset Password assistant pictured above.
4. Select ”My password doesn't work when logging in,” then click Next and follow the onscreen instructions for your user account.

Create a new login keychain, if necessary

After resetting your password and logging back in to your account, you might see an alert that the system was unable to unlock your login keychain. This is expected, because the passwords for your user account and login keychain no longer match. Just click the Create New Keychain button in the alert.

If you didn't see an alert about your login keychain, or you see other messages asking for your old password, reset your keychain manually:

1. Open Keychain Access, which is in the Utilities folder of your Applications folder.
2. Choose Preferences from the Keychain Access menu, then click the Reset My Default Keychain button in the preferences window. After you enter your new password, Keychain Access creates an empty login keychain with no password. Click OK to confirm.
   If you don't see a Reset My Default keychain button, close the preferences window and select the “login” keychain from the left side of the Keychain Access window. Press the Delete key, then click Delete References.
   
3. Choose Log Out from the Apple menu to return to the login screen.
4. Log in to your account using your new password. Your account password and login keychain password now match again.

If you still can't log in

If you still can't log in with your password, contact Apple Support for help.

How would you communicate with a device when you don’t have the IP?

You might be in a situation where you don’t have the IP address of a device in a local network, but all you have is records of the MAC or hardware address.

Or your computer is unable to display its IP due to various reasons, and you are getting a “No Valid IP Address” error.

Finding the IP from a known MAC address should be the task of a ReverseARP application, the counterpart of ARP.

But RARP is an obsolete protocol with many disadvantages, so it was quickly replaced by other protocols like BOOTP and DHCP, which deal directly with IP addresses.

In this article, we’ll show you how to find IPs and device vendors using MAC addresses with different methods for free.

Understanding ARP

ARP (Address Resolution Protocol) is the protocol in charge of finding MAC addresses with IPs in local network segments.

It operates with frames on the data link layer.

As you might already know, devices in the data link layer depend on MAC addresses for their communication.

Their frames encapsulate packets that contain IP address information.

A device must know the destination MAC address to communicate locally through media types like Ethernet or Wifi, in layer 2 of the OSI model.

Understanding how ARP works can help you find IPs and MAC addresses quickly.

The following message flow diagram can help you understand the concept:

1. The local computer sends a ping (ICMP echo request) to a destination IP address (remote computer) within the same segment. Unfortunately, the local computer does not know the MAC address… it only knows the IP address.
2. The destination hardware address is unknown, so the ICMP echo request is put on hold. The local computer only knows its source/destination IP and its source MAC addresses. ARP uses two types of messages, ARP Request and Reply.

The local computer sends an ARP REQUEST message to find the owner of the IP address in question.

This message is sent to all devices within the same segment or LAN through a broadcast MAC (FF:FF:FF:FF:FF:FF) as the destination.

1. Because the remote computer is part of the same network segment, it receives the broadcast message sent by the local computer. All other computers in the LAN also receive the broadcast but they know that the destination IP is not theirs, so they discard the packet. Only the remote computer with destination IP, responds to the ARP REQUEST with an ARP REPLY, which contains the target MAC address.
2. The local computer receives the ARP REPLY with the MAC address. It then resumes the ICMP echo request, and finally, the remote computer responds with an ICMP echo reply.

Finding IPs with ARP

You can use ARP to obtain an IP from a known MAC address.

But first, it is important to update your local ARP table in order to get information from all devices in the network.

Send a ping (ICMP echo reply) to the entire LAN, to get all the MAC entries on the table.

To ping the entire LAN, you can send a broadcast to your network.

Open the Command Prompt in Windows or terminal in macOS and type.

ping 192.168.0.255

My subnet is 192.168.0.0/24 (mask of 255.255.255.0), so the broadcast address is 192.168.0.255 which can be calculated or found with a “Print Route” command in Windows or a “netstat -nr” in macOS. Or can also be obtained with a subnet calculator.

For Windows:

Step 1.

• Open the CMD (Command Prompt)
• Go to the “Start” menu and select “Run” or press (Windows key + R) to open the Run application
• In the “Open” textbox type “cmd” and press “Ok”.

This will open the command-line interface in Windows.

Step 2.

• Enter the “arp” command.
• The arp command without any additional arguments will give you a list of options that you can use.

Step 3.

• Use the arp with additional arguments to find the IP within the same network segment.
• With the command “arp -a” you can see the ARP table and its entries recently populated by your computer with the broadcast ping.

Step 4.

• Reading the output.
• The information displayed in the arp-a is basically the ARP table on your computer.
• It shows a list with IP addresses, their corresponding physical address (or MAC), and the type of allocation (dynamic or static).

Let’s say you have the MAC address 60-30-d4-76-b8-c8 (which is a macOS device) and you want to know the IP.

From the results shown above, you can map the MAC address to the IP address in the same line.

The IP Address is 192.168.0.102 (which is in the same network segment) belongs to 60-30-d4-76-b8-c8.

You can forget about those 224.0.0.x and 239.0.0.x addresses, as they are multicast IPs.

For macOS:

Step 1:

Mac Os Versions

• Open the Terminal App. go to Applications > Utilities > Terminal or Launchpad > Other > Terminal.

Step 2:

• Enter the “arp” command with an “-a” flag.
• Once you enter the command “arp -a” you’ll receive a list with all ARP entries to the ARP Table in your computer.
• The output will show a line with the IP address followed by the MAC address, the interface, and the allocation type (dynamic/static).

Finding IPs with the DHCP Server

The Dynamic Host Configuration Protocol (DHCP) is the network protocol used by TCP/IP to dynamically allocate IP addresses and other characteristics to devices in a network.

The DHCP works with a client/server mode.

The DHCP server is the device in charge of assigning IP addresses in a network, and the client is usually your computer.

For home networks or LANs, the DHCP Server is typically a router or gateway.

If you have access to the DHCP Server, you can view all relationships with IPs, MACs, interfaces, name of the device, and lease time in your LAN.

Step 1.

• Log into the DHCP Server. In this example, the DHCP server is the home gateway.
• If you don’t know the IP address of your DHCP Server/ Gateway, you can run an ipconfig (in Windows) or ifconfig (in macOS/Linux).
• This particular DHCP Server/Gateway has a web interface.

Step 2.

• Enter the IP address on the search bar of the web browser, and input the right credentials.

Step 3.

• Find the DHCP Clients List.
• In this TP-Link router, the DHCP Server functionality comes as an additional feature.
• Go to DHCP > DHCP Clients List. From this list, you can see the mapping between MAC addresses and their assigned IPs.

Using Sniffers

Latest Mac Os

If you couldn’t find the IP in the ARP list or unfortunately don’t have access to the DHCP Server, as a last resort, you can use a sniffer.

Packet sniffers or network analyzers like Nmap (or Zenmap which is the GUI version) are designed for network security.

They can help identify attacks and vulnerabilities in the network.

With Nmap, you can actively scan your entire network and find IPs, ports, protocols, MACs, etc.

If you are trying to find the IP from a known MAC with a sniffer like Nmap, look for the MAC address within the scan results.

How to find the Device and IP with a Sniffer?

Step 1.

• Keep records of your network IP address information.
• In this case, my network IP is 192.168.0.0/24. If you don’t know it, a quick “ipconfig” in Windows cmd or an “ifconfig” in macOS or Linux terminal can show you the local IP and mask.
• If you can’t subnet, go online to a subnet calculator and find your network IP.

Step 2.

• Download and open Nmap.
• Download Nmap from this official link https://nmap.org/download.html and follow its straightforward installation process.

Step 3.

• Open Nmap (or Zenmap) and use the command “sudo nmap -sn (network IP)” to scan the entire network (without port scan).
• The command will list machines that respond to the Ping and will include their MAC address along with the vendor.
• Don’t forget the “sudo” command.
• Without it, you will not see MAC addresses.

Finding out the device vendor from a MAC address

Ok, so now you were able to find out the IP address using “arp -a” command or through the DHCP Server.

But what if you want to know more details about that particular device?

What vendor is it?

Your network segment or LAN might be full of different devices, from computers, firewalls, routers, mobiles, printers, TVs, etc.

And MAC addresses contain key information for knowing more details about each network device.

First, it is essential to understand the format of the MAC address.

Traditional MAC addresses are 48 bits represented in 12-digit hexadecimal numbers (or six octets).

The first half of the six octets represent the Organizational Unique Identifier (OUI) and the other half is the Network Interface Controller (NIC) which is unique for every device in the world.

There is not much we can do about the NIC, other than communicating with it.

But the OUI can give us useful information about the vendor if you didn’t use Nmap, which can also give you the hardware vendor.

A free online OUI lookup tool like Wireshark OUI Lookup can help you with this.

Just enter the MAC address on the OUI search, and the tool will look at the first three octets and correlate with its manufacturing database.

Final Words

Although the RARP (the counterpart of ARP) was specifically designed to find IPs from MAC addresses, it was quickly discontinued because it had many drawbacks.

RARP was quickly replaced by DHCP and BOOTP.

But ARP is still one of the core functions of the IP layer in the TCP/IP protocol stack.

It finds MAC addresses from known IPs, which is most common in today’s communications.

ARP works under the hood to keep a frequently used list of MACs and IPs.

But you can also use it to see the current mappings with the command arp -a.

Aside from ARP, you can also use DHCP to view IP information. DHCP Servers are usually in charge of IP assignments.

If you have access to the DHCP server, go into the DHCP Client list and identify the IP with the MAC address.

Finally, you can use a network sniffer like Nmap, scan your entire network, and find IPs, and MACs.

Id Device For Mac Os 10.10

If you only want to know the vendor, an online OUI lookup like Wireshark can help you find it quickly.