We have changed the mother board

The address is exactly that, an address.
In a network where many devices comun?cate with each other, the network control directs communication of any sort from one address to another address or groups of addresses. Similar to postal mail, the post office as the network controller receives and delivers mail or data to an address or MAC identifier address.

You can change mac-address of SCUB on Huawei OLT MA5680T in following way:
1. First you have to login as root user
2. You will have to enter in diagnose mode with following commands:
huawei(config)#diagnose
huawei(diagnose)%
3. you have to check which mac address is currently in the system by command:
huawei(diagnose)% display sysman mac-address
Current MAC address of active mainboard: 0025-1c54-c45c
Default MAC address of active mainboard: 0025-1c54-d0763
4. Changing mac-address you can done with command:
huawei(diagnose)%sysman mac-address current 0025-1c54-c455
Command:
sysman mac-address current 0025-1c54-c455
Modifying current MAC address may cause the conflict of MAC address, are you
sure?(y/n) [n]:y
5. Last step is to reboot board on which you have change mac-address or to reboot system. In this way new mac-address will be applied to the SCUB board

I think this is what your talking about:
http://www.instructables.com/id/How-To-Manually-Merge-Gmail-Account-With-Apple-Mai/

Hello, if you go onto properties of your NIC, click 'advanced' , go down to 'locally administered address' ; this is the bit where you can enter your own mac address. See this page or google 'locally administered address'http://www.javvin.com/networkingterms/LAA.html

regards,nicam49

plug in first to the network, and if exist comunication, go through the settings, and you be abel to see the net configuration, (IP selection, IPaddress, SubnetMask and Gateway.
check behind the printer nex to the net connectio, possible have a stiker, if not, try the stiker at the logic board.

First, you have to directly attach to the cable modem whichever computer the instal tech used to establish your account. Make sure that connection works. Then re-insert the router and clone the MAC address of the instal computer to the router. Then check your DHCP settings. Make sure it's set to get a new IP from your new provider. You may then have to then release your IP and resubscribe.

There is no way to change the MAC address, but you can make Windows tell the system it has a different address that might fool your other program. Follow the instructions below.
Change the MAC address in Windows

1. Go to Start -> Control Panel. Double click on Network Connections (inside Network and Internet Connections category in Windows XP). The, right click on the active network connection with network adapter that you want to change the MAC address (normally Local Area Network or Wireless Network Connection) and click on Properties. Above steps work in Windows XP, Windows 2000 and Windows Server 2003 . For Windows Vista, access to NIC’s properties is from Control Panel -> Network and Internet -> Network and Sharing Center -> Manage Network Connections.
   Alternatively, if you already know which network adapter that’s responsible for your network or Internet connection, go to Device Manager and open the properties dialog by double click on the NIC itself.
   
2. In the General tab, click on the Configure button.
3. Click on Advanced tab.
4. In the Property section, select and highlight Network Address or Locally Administered Address.
5. To the right, “Not Present” radio button is by default selected as value. Change the value by clicking on radio button for Value:, and then type in a new MAC address to assign to the NIC. The MAC address consists of 6 pairs of numbers (0 - 9) and characters (A - F) combination. For example, 88-17-E8-90-E2-0A. When entering the new MAC value, omit the dash (-), for example 8817E890E20A.
   
6. Click OK when done.
7. To verify the change of MAC address, go to command prompt, then type in one of the following commands: ipconfig /all
   net config rdr
   
8. Reboot the computer if successful to make the change effective.

Using the Configuration Menu
Note: if you have changed the default IP Address assigned to the DI-624, make sure to enter the correct IP Address.



 Open the web browser
 Type in the IP Address of
the Router (http://192.168.0.1)

12 Type admin in the User Name field
Leave the Password blank
Click OK
Home > Wizard
The Home>Wizard screen will appear. Please refer to the Quick Installation Guide for more information regarding the Setup Wizard.
.
These buttons appear on most of the configuration screens in this section. Please click on the appropriate button at the bottom of each screen after you have made a configuration change.
.
.
.13
Using the Configuration Menu (continued)
Home > Wireless
Service Set Identifier (SSID) is the name designated for a specific wireless local area network (WLAN). The SSID’s factory default setting is default. The SSID can be easily changed to connect to an existing wireless network or to establish a new wireless network.
SSID-
Channel-
6 is the default channel. All devices on the network must share the same channel. (Note: The wireless adapters will automatically scan and match the wireless setting.)
WEP-
Wired Equivalent Privacy (WEP) is a wireless security protocol for Wireless Local Area Networks (WLAN). WEP provides security by encrypting the data that is sent over the WLAN. Select Enabled or Disabled. Disabled is the default setting. (Note: If you enable encryption on the DI-624 make sure to also enable encryption on all the wireless clients or wireless connection will not be established.)
WEP Encryption-
Select the level of encryption desired: 64-bit, or 128-bit.
Key Type-
Select HEX or ASCII.
Keys 1-4-
Input up to 4 WEP keys; select the one you wish to use.14
Using the Configuration Menu (continued)
Home > WAN > Dynamic IP Address
DI-754
Dynamic
IP Address-
Choose Dynamic IP Address to obtain IP Address information automatically from your ISP. Select this option if your ISP does not give you any IP numbers to use. This option is commonly used for Cable modem services.
Host Name-
The Host Name is optional but may be required by some ISPs. The default host name is the device name of the Router and may be changed.
MAC Address-
The default MAC Address is set to the WAN’s physical interface MAC address on the Broadband Router. It is not recommended that you change the default MAC address unless required by your ISP.
Clone
MAC Address-
The default MAC address is set to the WAN’s physical interface MAC address on the Broadband Router. You can use the "Clone MAC Address" button to copy the MAC address of the Ethernet Card installed by your ISP and replace the WAN MAC address with the MAC address of the router. It is not recommended that you change the default MAC address unless required by your ISP.
Enter a DNS Address if you do not wish to use the one provided by your ISP.
Primary/
Secondary DNS Address-
MTU-
Enter an MTU value only if required by your ISP. Otherwise, leave it at the default setting.15
Home > WAN > Static IP Address
Static IP Address-
Choose Static IP Address if all WAN IP information is provided to you by your ISP. You will need to enter in the IP address, subnet mask, gateway address, and DNS address(es) provided to you by your ISP. Each IP address entered in the fields must be in the appropriate IP form, which are four octets separated by a dot (x.x.x.x). The Router will not accept the IP address if it is not in this format.
IP Address-
Input the public IP Address provided by your ISP.
Subnet Mask-
Input your Subnet mask. (All devices in the network must have the same subnet mask.)
ISP
Gateway Address-
Input the public IP address of the ISP to which you are connecting.
Primary
DNS Address-
Input the primary DNS (Domain Name Server) IP address provided by your ISP.
Secondary
DNS Address-
This is optional.
Enter an MTU value only if required by your ISP. Otherwise, leave it at the default setting.

This might help your quest:

http://64.223.189.234/node/891

This document is relevant if you had an Internet connection, but lost it when: * Adding a router to your network, or * Using a different Ethernet adapter card or computer than the one your ISP used during installation. Use ISP Configuration to see whether you need to "spoof a MAC address" to connect to your ISP. If so, follow the instructions in this document. If the Ethernet card that was used during ISP installation is not available, you may need to register the new Ethernet card's MAC address with your ISP for the following to work. MAC address stands for Media Access Control address (not "Macintosh computer"!), a unique number built into modems, routers and other network hardware. It ensures that one piece of equipment is not mistaken for another one. Some ISPs validate your connection by checking the MAC address of the Ethernet adapter in computer that was registered during ISP installation. If you add a router or change computer or Ethernet adapter, these ISPs will drop your Internet connection, because they find the MAC address of the newly added router or adapter, instead of the one they expect. To fix this, change the router to report the Ethernet adapter's MAC, instead of its own. This is called "spoofing the MAC address". To find a PC's or Macintosh's MAC address, see How to Find an Adapter's MAC address : http://www.fixya.com/ThreadView.aspx?prdid=252225&thid=102075. To Spoof a MAC Address 1. Connect the computer that your ISP's installers used to establish Internet connection to the router. If you are unsure which computer was used, call your ISP, and ask what MAC address was registered. Then, using the instructions in the box below find the computer whose MAC address matches their records. 2. Disconnect other computers from the router. (If you do not want to disconnect other computers, you need to know the adapter's MAC address, as described in the box below. Then, in step 6, type Use This MAC Address, entering the adapter's address.) 3. In an Internet browser type the address 192.168.0.1. 4. Type admin for the username, password for the password, and click OK. 5. Go to the Basic Settings > Router Mac Address. 6. Select Use Computer MAC Address. 7. Click Apply. This automatically gives the router the computer's MAC address. 8. Click Test to make sure you are connected. If you are not connected, contact your ISP.