The answer to the question “Media Access Control
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In recent weeks, I have several e-mails about Ethernet cards, for both wireline and wireless, and in particular on the Media Access Control (MAC) addresses. I think the main reason why I have so many questions about Ethernet cards and the MAC addresses is people trying their wireless networks and their desire to Filtering MAC addresses. This type of filtering in wireless networks can be configured to allow or refuse to use the computer or to be set for the wireless network based on MAC address.

My first thought was to write an article on the MAC addresses Ethernet and wireless. After more than her, I decided for them and specific information on certain Ethernet cards and communication.

Different options, your MAC address and More
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There are several ways to find your communication and Ethernet protocol information. Many Ethernet card manufacturer’s have proprietary software, this information, but they function according to the manufacturers. To use Windows 2000 and XP “ipconfig”, because the program is in most Windows operating systems.

First, go to Start -> Run and type “cmd” without quotes. Then press Enter. On the command line, type “ipconfig / all” again without quotes. In fact, just without the ipconfig / all the work, but only on a case by case, abbreviated information about your network card. An example of what you can see by typing “ipconfig / all” command is reviewed each article in green:

At fault tolerance and availability of system
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There are several ways to find your communication and Ethernet protocol information. Many Ethernet card manufacturer’s have proprietary software, this information, but they function according to the manufacturers. To use Windows 2000 and XP “ipconfig”, because the program is in most Windows operating systems.

First, go to Start -> Run and type “cmd” without quotes. Then press Enter. On the command line, type “ipconfig / all” again without quotes. In fact, just without the ipconfig / all the work, but only on a case by case, abbreviated information about your network card. An example of what you can see by typing “ipconfig / all” command is:

Edition of “ipconfig / all” command
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Windows IP Configuration

Hostname. . . . . . . . . . . . : Home Computer
This is the name of the computer, typically defined when you install Windows. It can be adjusted after installation.

Primary DNS Suffix. . . . . . . : Domain.com
If your computer is connected to a network, such as a Microsoft Windows domain this article, you can the domain name.

Node. . . . . . . . . . . . : Unknown
The knot can be said, of unknown type, or peer-to-peer, or, in some cases “hybrid”. It is a parameter that has to do with the Windows Internet Naming Services for certain types of Windows domain networks.

IP routing enabled. . . . . . . . : No
This setting determines whether Windows XP or 2000, is regarded as an IP router. If you have two or more network cards in your system, you can act as a router, forwarding communications by an access network to another. Windows 2000 can be configured to do this in a fairly simple, Windows XP, an amendment of records.

Proxy WINS enabled. . . . . . . . : No
WINS proxy is another argument in the context of the “knot” we discussed earlier. It is, in general, is not a setting you want in a home or small office network or a new type of Microsoft Windows.

Ethernet adapter Wireless Network Connection 2:
If you have multiple Ethernet (network) card on your system, as I am in this laptop, you have several offers. This occurs, the second Ethernet card, internal wireless Ethernet card.

Description. . . . . . . . . . . : Broadcom 802.11b / g WLAN
This is the description of the Ethernet card, usually the name / manufacturer and type of Ethernet card. In this case, it is a Broadcom wireless Ethernet card in my laptop.

Physical address. . . . . . . . . : 00-90-4B-F1-6E-4A
And here we have the MAC address. The MAC address is a 48-bit hexadecimal code and suppose, for a unique address. It is 48 bits because each number or letter in hexadecimal represents 8 bits. Hexadecimal numbers from 0,1,2,3,4,5,6,7,8,9, A, B, C, D, E, F. There are 6-alpha-numeric codes of 6 * 8 = 48 (bits). The first 3 codes identify the manufacturer of the card and other codes are used to a unique number. In theory, there should never a card with the same MAC address on a LAN. There are some exceptions. There are software tools that allow you to change the code. Indeed, it is a step some hackers to attack other systems via a LAN. I say local network because MAC addresses are not routable between network segments. The theft of this address, you can the identity of another machine on the LAN. Transport, the target for the redirect, so that hackers machine. This is the address that you can use to populate a MAC address or physical address table for the configuration of your wireless access point for MAC Address Filtering.

DHCP enabled. . . . . . . . . . . : Yes
DHCP, or Dynamic Host Control Protocol, if enabled, means that your computer IP address from a DHCP server on your network. The DHCP server, you can wireless access point Cable / DSL, cable modem or a server on your network. In addition, if a DHCP server is not enabled on your network operating system is automatically a random IP address in a predefined area. This means you can, a group of networking systems, without manual assignment of IP parameters.

IP address. . . . . . . . . . . . : 192.168.0.117
This setting offers you, with your current IP address. The above address is what is a “private” address. There are certain types of IP addresses were intended for private use. Ie internal, local or private network at home or office. Such addresses are not, or not routable on the Internet. Internet connections known as “valid” IP addresses. Cable / DSL or cable modem has an IP address assigned to its “external” network interface. The external interface, you can phone or cable TV cable.

Subnet mask. . . . . . . . . . . : 255.255.255.0
The subnet mask is a number, or in some way, filters, breaks, your IP address, in which case the private IP address, in some groups. IP addresses and subnet masks can be a complex issue and would be an article to go.

Default Gateway. . . . . . . . . : 192.168.0.254
The default gateway, IP addresses, the IP address of the device, the route of your application, for example, if you try, for a website on the Internet. It is a bit more complicated if, as the gateway or router can route traffic to different networks, other private networks. At home, at home or small office, the door is most likely your cable / DSL modem or router.

DHCP server. . . . . . . . . . . : 192.168.0.49
The DHCP server, let us recall a little before, the device is that your computer IP address and other information. DHCP server, all types of information, for example, the default gateway, DNS (Domain Name Server), IP address, subnet mask, time server, and more.

DNS server. . . . . . . . . . . : 192.168.0.49, 64.105.197.58
DNS server, it is internal or external server, the solution Fully Qualified Domain Names (FQDN) as www.defendingthenet.com for IP addresses. This occurs because the computer, they do not, your application with the domain name, use the IP address, FQDN. For most in the home or small office user, the primary DNS server on the IP address of your cable / DSL Router. Cable / DSL Router Queries as an external DNS server on the Internet to determine the resolution of FQDN of the IP address. The address 192.168.0.49 is a private network in my mind that one is 64.105.197.58 external public Internet DNS server is available only for the case, my router has problems, the tasks of DNS resolution.

Lease Obtained. . . . . . . . . . Sunday, March 19, 2006 6:38:16 PM
This information, you will know if your computer get their IP address and other information from a DHCP server. You can see, it says “Lease obtained is that most of the DHCP servers only lease the IP address for you from a pool of addresses available. For example, you can use your pool 192168 .1.1 by 192.168.1.50. So, the DHCP server has 50 IP addresses to choose, at the time of your computer’s IP address.

Expiration of the lease. . . . . . . . . . Wednesday, March 29, 2006 9:38:16 PM
If the IP address by the DHCP server, the lease is to try to rent the same or another IP address. This function can be changed in general on the DHCP server. For example, some fully functional DHCP server, you can lease never expires, or before the expiration of 1 day and so on.

Why the MAC address is so important and how do they
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Jump back to the MAC address for only a little. They believe that IP addresses are most important when it comes to network communication. The reality is, MAC addresses are very important because without the computer would not be able to communicate over Ethernet networks. If a computer wants to talk to another computer on a LAN, it is a question of distribution, or ask a question, which has a specific IP address. For example, your computer may be saying, “Who is 192.168.0.254. With the help of the information above, my default gateway is 192.168.0.254 and the answer is “I” 00-90-4B-F1-6E-4A “192.168.0.254″. It sends its MAC address. The MAC address is in what is called ARP (Address Resolution Protocol) in the table on your computer. You can access this information using the command prompt, you have above and the entry of “arp-a”. You will receive information, such as:

Internet Address Physical Address Type
192.168.0.49 00-12-17-5 c-A2-27 in a dynamic way
192.168.0.109 00-12-17-5 c-A2-27 in a dynamic way
192.168.0.112 00-0C-76-93-94-B2 dynamic
192.168.0.254 00-0E-2E-2E-15-61 dynamic

How can an attacker MAC addresses in an attack
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You can see IP addresses and to give them the MAC addresses. Without this information, without the MAC address, you would not be reading this article now. MAC addresses are not routable IP addresses as. They work on the local network or private. However, devices of the Internet the same functions. Routers and switches, a list of the MAC address of Peer-computer and peripherals such as devices in your home or office network. I mentioned the above, the MAC addresses can be changed to redirect. For example, if I’m on the office network and you have an internal Web server, personal data as input, I would say go to your computer to my laptop to the website of the dissemination of my MAC to the real address of web server IP address. I want to do when the computer question “Who is the Real-Web-Server”. I could install a fake web server, which resembles the original, and gather information, the real web servers, in Generally, together. You can see how can be dangerous.

Conclusion
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There are several easy ways to find your MAC address, but it may be a little confusing if you have more than one internal network card. Most external USB or PCMCIA wired Ethernet and wireless cards have their MAC address on them. Where the wireless or a wireless network card in your computer, such as laptops, the MAC address is sometimes on the merits of the laptop. In addition, Office Systems of cards in the PCI slots are on the MAC address of the Ethernet card.