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MACAddress

• What Windows Utility Do You Use To Find The Mac Address For A Systematic
• What Windows Utility Do You Use To Find The Mac Address For A System

How to find MAC address using PowerShell. To find the MAC address with PowerShell, use these steps: Open Start. Search for PowerShell and click the top result to open the app. Windows 10, 8, 7, Vista: Click Windows Start or press the Windows key. In the search box, type cmd.

In computer networking, the Media AccessControl (MAC) address is every bit as important as an IPaddress. Learn in this article how MAC addresses work and how to find the MACaddresses being used by a computer.

What Is a MAC Address?

TheMAC address is a unique value associated with a network adapter. MAC addressesare also known as hardware addresses or physical addresses. Theyuniquely identify an adapter on a LAN.

MAC addresses are 12-digit hexadecimalnumbers (48 bits in length). By convention, MAC addresses are usually writtenin one of the following formats:

MM:MM:MM:SS:SS:SS

MMMM-MMSS-SSSS

Thefirst half (24 BITS) of a MAC address contains the ID number of the adaptermanufacturer. These IDs are regulated by an Internet standards body (seesidebar). The second half (24 MORE BITS) of a MAC address represents the serialnumber assigned to the adapter by the manufacturer. In the example,

00:A0:C9:14:C8:29

Theprefix

00A0C9

indicates the manufacturer is Intel Corporation.

Why MAC Addresses?

Recallthat TCP/IP and other mainstream networking architectures generally adopt theOSI model. In this model, network functionality is subdivided into layers. MACaddresses function at the data link layer (layer 2 in the OSI model). Theyallow computers to uniquely identify themselves on a network at this relativelylow level.

MAC vs. IP Addressing

WhereasMAC addressing works at the data link layer, IP addressing functions at thenetwork layer (layer 3). It's a slight oversimplification, but one can think ofIP addressing as supporting the software implementation and MAC addresses assupporting the hardware implementation of the network stack. The MAC addressgenerally remains fixed and follows the network device, but the IP addresschanges as the network device moves from one network to another.

IP networks maintain a mapping(association) between the IP address of a device and its MAC address. Thismapping is known as the ARP cache or ARP table. ARP, the AddressResolution Protocol, supports the logic for obtaining this mapping and keepingthe cache up to date.

DHCP also usually relies on MAC addressesto manage the unique assignment of IP addresses to devices.

The method used to find a MAC addressdepends on the type of network device involved. All popular network operatingsystems contain utility programs that allow one to find (and sometimes change)MAC address settings.

Find a MAC Address inWindows

InWindows 95, Windows 98 and Windows ME, the winipcfg utility displays MACaddresses. In Windows NT and any newer versions of Windows, the ipconfig utility (using the /all option) can also beused.

Both winipcfg and ipconfig can display multiple MAC addresses. First, one MACaddress is shown for each network adapter. Then, one or more additional MACaddresses are shown for other network adapters.

Windows, for example, utilizes built-inMAC addressing to support Windows dial-up connections. Some Windows VPN clientslikewise use their own MAC address. Because these other adapters are reallysoftware constructs that do not involve unique hardware, these are oftenreferred to as virtual adapters.

Find a MAC Address in Unix or Linux

Thespecific command used in Unix to find a MAC addressvaries depending on the 'flavor' of the operating system. In Linuxand in some forms of Unix, the command ifconfig-areturns MAC addresses.

It's also possible to find MAC addressesin Unix and Linux by reading the boot messagesequence, either on-screen as the system boots or from the startup messagefile. The log file for boot messages is usually /var/log/messagesor /var/adm/messages.

Find a MAC Address onthe Macintosh

MACaddresses on the Macintosh are generally found on the TCP/IP Control Panel.If the system is running Open Transport, the MAC address can be found under theInfo or User Mode/Advanced screens. If the system is running MacTCP, the MAC address can be found under the Etherneticon.

Finding a MAC AddressSummary

The table below summarizes options forfinding a computer's MAC address.

MAC addresses were designed to be fixednumbers that cannot be changed. However, there are some valid reasons to wantto change your MAC address.

Changing MAC Addressesto Support Your ISP

Some ISPs, typically cable modemproviders, sell Internet subscriptions on a per-address basis. Occasionally theISP manages these subscriptions by assigning a static (fixed) IP address to thecustomer. However, this approach is an inefficient use of IP addresses that arecurrently in short supply.

More typically, ISPs manage single-addresssubscriptions by registering the MAC address of the device that connects to theISP. This device could be a broadband modem, for example. The customer is freeto build a home or small business network behind this modem, but the ISPexpects the MAC address to match the registered value at all times.

Whenever a customer replaces their modemor adds a broadband router, the MAC address will no longer match thatregistered at the ISP, and the ISP will disable the customer's Internetconnection.

Cloning MAC Addresses

One way to solve this problem is to callthe ISP and ask them to update the registered MAC address to match the newhardware. A more efficient way to solve this problem is to configure the deviceso that it advertises the original MAC address, even though it'shardware is built to utilize a different MAC address. This process is called cloning.

Many broadband routers today support MACaddress cloning as an advanced configuration option. The exact procedure variesdepending on the type of router.

MAC Addresses and CableModems

Note that in addition to MAC addressesstored at the ISP, some broadband modems also store the MAC address of the hostcomputer's network adapter. However, in this case, cloning is not required.It's true that changing network adapters usually causes the cable modemconnection to fail. To remedy this problem, though, requires only that thecable modem and computer be reset (and perhaps a waiting period for the ISP torelease the old IP address).

Changing MAC Addressesthrough the Operating System

Starting with Windows 2000, users canchange their MAC address through the Windows My Network Placesinterface. This feature relies on software support built into the adapterdriver program and thus does not work for all adapters.

Likewise, the ifconfig command available in Linux and other flavors of Unix supports changing MAC addresses with the necessarynetwork card and driver support.

In Conclusion

The MAC address is an important element ofcomputer networking. MAC addresses uniquely identify a computer on the LAN. MACis an essential component required for network protocols like TCP/IP tofunction.

Computer operating systems and broadbandrouters support viewing and sometimes changing MAC addresses. Some ISPs tracktheir customers by MAC address. Changing a MAC address can be necessary in somecases to keep an Internet connection working.

Changing MAC addresses may also increaseprivacy in some situations, though MAC addresses do not reveal any geographicor ISP location information like IP addresses do.

Directory Utility User Guide

Important: With the advanced options of the Active Directory connector, you can map the macOS unique user ID (UID), primary group ID (GID), and group GID attributes to the correct attributes in the Active Directory schema. However, if you change these settings later, users might lose access to previously created files.

Bind using Directory Utility

1. In the Directory Utility app on your Mac, click Services.

2. Click the lock icon.

3. Enter an administrator’s user name and password, then click Modify Configuration (or use Touch ID).

4. Select Active Directory, then click the “Edit settings for the selected service” button .

5. Enter the DNS host name of the Active Directory domain you want to bind to the computer you’re configuring.

   The administrator of the Active Directory domain can tell you the DNS host name.

6. If necessary, edit the Computer ID.

   The Computer ID, the name the computer is known by in the Active Directory domain, is preset to the name of the computer. You can change it to conform to your organization’s naming scheme. If you’re not sure, ask the Active Directory domain administrator.

   Important: If your computer name contains a hyphen, you might not be able to bind to a directory domain such as LDAP or Active Directory. To establish binding, use a computer name that does not contain a hyphen.

7. If the advanced options are hidden, click the disclosure triangle next to Show Options. You can also change advanced option settings later.

8. (Optional) Select options in the User Experience pane.

   See Set up mobile user accounts, Set up home folders for user accounts, and Set a UNIX shell for Active Directory user accounts.

9. (Optional) Select options in the Mappings pane.

   See Map the group ID, Primary GID, and UID to an Active Directory attribute.

10. (Optional) Select options in the Administrative pane.

    • Prefer this domain server: By default, macOS uses site information and domain controller responsiveness to determine which domain controller to use. If a domain controller in the same site is specified here, it’s consulted first. If the domain controller is unavailable, macOS reverts to default behavior.

    • Allow administration by: When this option is enabled, members of the listed Active Directory groups (by default, domain and enterprise admins) are granted administrative privileges on the local Mac. You can also specify desired security groups here.

    • Allow authentication from any domain in the forest: By default, macOS automatically searches all domains for authentication. To restrict authentication to only the domain the Mac is bound to, deselect this checkbox.

    See Control authentication from all domains in the Active Directory forest.

11. Click Bind, then enter the following information:

    Note: The user must have privileges in Active Directory to bind a computer to the domain.

    • Username and Password: You might be able to authenticate by entering the name and password of your Active Directory user account, or the Active Directory domain administrator might need to provide a name and password.

    • Computer OU: Enter the organizational unit (OU) for the computer you’re configuring.

    • Use for authentication: Select if you want Active Directory added to the computer’s authentication search policy.

    • Use for contacts: Select if you want Active Directory added to the computer’s contacts search policy.

12. Click OK.

    Directory Utility sets up trusted binding between the computer you’re configuring and the Active Directory server. The computer’s search policies are set according to the options you selected when you authenticated, and Active Directory is enabled in Directory Utility’s Services pane.

    With the default settings for Active Directory advanced options, the Active Directory forest is added to the computer’s authentication search policy and contacts search policy if you selected “Use for authentication” or “Use for contacts.”

    However, if you deselect “Allow authentication from any domain in the forest” in the Administrative Advanced Options pane before clicking Bind, the nearest Active Directory domain is added instead of the forest.

    You can change search policies later by adding or removing the Active Directory forest or individual domains. See Define search policies.

Bind using a configuration profile

The directory payload in a configuration profile can configure a single Mac, or automate hundreds of Mac computers, to bind to Active Directory. As with other configuration profile payloads, you can deploy the directory payload manually, using a script, as part of an MDM enrollment, or by using a client-management solution.

Payloads are part of configuration profiles and allow administrators to manage specific parts of macOS. You select the same features in Profile Manager that you would in Directory Utility. Then you choose how the Mac computers get the configuration profile.

In the Server app on your Mac, do the following:

• To configure Profile Manager, see Start Profile Manager in the macOS Server User Guide.

• To create an Active Directory payload, see Directory MDM payload settings for Apple devices in Mobile Device Management Settings for IT Administrators.

If you don’t have the Server app, you can download it from the Mac App Store.

Bind using the command line

You can use the dsconfigad command in the Terminal app to bind a Mac to Active Directory.

For example, the following command can be used to bind a Mac to Active Directory:

After you bind a Mac to the domain, you can use dsconfigad to set the administrative options in Directory Utility:

What Windows Utility Do You Use To Find The Mac Address For A Systematic

Advanced command–line options

The native support for Active Directory includes options that you don’t see in Directory Utility. To see these advanced options, use either the Directory payload in a configuration profile; or the dsconfigad command–line tool.

• Start reviewing the command–line options by opening the dsconfigad man page.

Computer object password interval

When a Mac system is bound to Active Directory, it sets a computer account password that’s stored in the system keychain and is automatically changed by the Mac. The default password interval is every 14 days, but you can use the directory payload or dsconfigad command–line tool to set any interval that your policy requires.

Setting the value to 0 disables automatic changing of the account password: dsconfigad -passinterval 0

Note: The computer object password is stored as a password value in the system keychain. To retrieve the password, open Keychain Access, select the system keychain, then select the Passwords category. Find the entry that looks like /Active Directory/DOMAIN where DOMAIN is the NetBIOS name of the Active Directory domain. Double-click this entry, then select the “Show password” checkbox. Authenticate as a local administrator as needed.

Namespace support

macOS supports authenticating multiple users with the same short names (or login names) that exist in different domains within the Active Directory forest. By enabling namespace support with the Directory payload or the dsconfigad command–line tool, a user in one domain can have the same short name as a user in a secondary domain. Both users have to log in using the name of their domain followed by their short names (DOMAINshort name), similar to logging in to a Windows PC. To enable this support, use the following command:

dsconfigad -namespace <forest>

Packet signing and encryption

The Open Directory client can sign and encrypt the LDAP connections used to communicate with Active Directory. With the signed SMB support in macOS, it shouldn’t be necessary to downgrade the site’s security policy to accommodate Mac computers. The signed and encrypted LDAP connections also eliminate any need to use LDAP over SSL. If SSL connections are required, use the following command to configure Open Directory to use SSL:

dsconfigad -packetencrypt ssl

Note that the certificates used on the domain controllers must be trusted for SSL encryption to be successful. If the domain controller certificates aren’t issued from the macOS native trusted system roots, install and trust the certificate chain in the System keychain. Certificate authorities trusted by default in macOS are in the System Roots keychain. To install certificates and establish trust, do one of the following:

What Windows Utility Do You Use To Find The Mac Address For A System

• Import the root and any necessary intermediate certificates using the certificates payload in a configuration profile

• Use Keychain Access located in /Applications/Utilities/

• Use the security command as follows:

  /usr/bin/security add-trusted-cert -d -p basic -k /Library/Keychains/System.keychain <path/to/certificate/file>

Restrict Dynamic DNS

macOS attempts to update its Address (A) record in DNS for all interfaces by default. If multiple interfaces are configured, this may result in multiple records in DNS. To manage this behavior, specify which interface to use when updating the Dynamic Domain Name System (DDNS) by using the Directory payload or the dsconfigad command–line tool. Specify the BSD name of the interface in which to associate the DDNS updates. The BSD name is the same as the Device field, returned by running this command:

networksetup -listallhardwareports

When using dsconfigad in a script, you must include the clear-text password used to bind to the domain. Typically, an Active Directory user with no other administrator privileges is delegated the responsibility of binding Mac computers to the domain. This user name and password pair is stored in the script. It’s common practice for the script to securely delete itself after binding so this information no longer resides on the storage device.