Tuesday, October 25, 2011

How to Determine Your Device's Ethernet or Wireless Hardware Address

All manufacturers of Ethernet and Wireless interfaces cooperate to ensure that every hardware interface has a unique address.
If your computer has both an Ethernet interface and a Wireless interface, each will have its own unique hardware address.
An Ethernet or Wireless hardware address is a 6-byte hexadecimal number; for example: 0x080007A9B2FC. (Each byte is written as two hexadecimal digits, so there are twelve hexadecimal digits; each hex digit is a number from 0-9 or a letter from A-F. A leading '0x' may be written to make explicit that the following digits should interpreted as hexadecimal.)
Ethernet and Wireless hardware addresses are often written in other forms, to make them easier to understand. It is common to leave off the leading '0x', and also to separate the six pairs of digits with colons or dashes, like: 08:00:07:A9:B2:FC or 00-00-94-ba-0e-cc. When using colons or dashes to separate the address into six pairs, sometimes any leading zero in each pair of digits is dropped; e.g. 8:0:7:A9:B2:FC or 0:0:94:ba:e:cc. (Note that when dropping leadings zeroes, '00' becomes '0' -- you never completely eliminate any of the six pairs of digits.)

Windows 95, 98, ME

The process of obtaining your ethernet address is fairly simple in Windows 95, Windows 98, and Windows ME. You need to have, at least, installed the Microsoft TCPIP protocol to use this method. If you have installed the MS TCPIP protocol do the following:
  1. Click on Start.
  2. Click on Run.
  3. In the command line box which appears, enter the following and press the Enter key:
    winipcfg
    
  4. A box will appear with a variety of information. Check the pull-down menu near the top to verify that your Ethernet interface is selected; if it is not, then select it in this menu.
  5. Look for the line labelled Adapter Address. This is your Ethernet interface's hardware address. It will be written out completely as 6 pairs of 2 digits separted by hyphens. Write it down.
  6. If your machine has a wireless card, select Wireless interface from the drop down menu. Look for the Adapter Address under this section and write it down.

Windows NT 4.0

You can find your ethernet address using Microsoft's ipconfig utility:
  1. Click the Start button.
  2. Select Programs and then select Command Prompt.
  3. At the C:\> prompt, enter the following then press the Enter key:
    ipconfig /all
    
  4. Your machine's ethernet address is listed as the Physical Address.
  5. If your machine has both an Ethernet and a Wireless connection, two Physical Adresses will be shown in different sections. The Ethernet hardware address is listed under Ethernet Adapter Local Area Connection and the Wireless hardware address will be listed under Ethernet Adapter Wireless Network Connection.
  6. To close the Command Prompt window, enter the following at the C:\> prompt then press the Enter key:
    exit
    

Windows 2000, XP

You can find your machine's Ethernet or Wireless hardware addresses using Microsoft's ipconfig utility:
  1. Click the Start button.
  2. Select Programs and then select Accessories/Command Prompt.
  3. At the C:\> prompt, enter the following then press the Enter key:
    ipconfig /all
    
  4. Your machine's Ethernet or Wireless hardware address is listed as the Physical Address.
  5. If your machine has both an Ethernet and a Wireless connection, two Physical Adresses will be shown in different sections. The Ethernet hardware address is listed under Ethernet Adapter Local Area Connection and the Wireless hardware address will be listed under Ethernet Adapter Wireless Network Connection.
  6. To close the Command Prompt window, enter the following at the C:\> prompt then press the Enter key:
    exit
    

Windows Vista, Windows 7

You can find your machine's Ethernet or Wireless hardware addresses using Microsoft's getmac utility:
  1. If your device is a Dell laptop, ensure it is plugged into an electrical outlet; if it is not plugged in, the device's Ethernet address will not be displayed.
  2. Click the Start button.
  3. In the Search box, enter the following then press the Enter key:
    cmd
    
  4. At the DOS prompt, enter the following then press the Enter key:
    getmac /v
    
  5. Your machine's Ethernet or Wireless hardware addresses are listed as the Physical Addresses.
  6. If your machine has both an Ethernet and a Wireless connection, two Physical Adresses will be shown in different sections. The Ethernet hardware address is listed under Ethernet Adapter Local Area Connection and the Wireless hardware address will be listed under Ethernet Adapter Wireless Network Connection.
  7. To close the Command Prompt window, enter the following at the C:\> prompt then press the Enter key:
    exit
    

Mac OS X 10.4, 10.5, 10.6, 10.7

To display your Mac OS X device's Ethernet or Wireless hardware addresses:
  1. Make sure that the network interface you're interested in is part of the current location, and is turned "on":
    1. Open the System Preferences application in the Apple menu.The System Preferences application is also sometimes available in the Dock. It's also available in the Utilities folder (in versions 10.4 - 10.5) or the Applications folder (in versions 10.6 - 10.7).
    2. Click the Network icon in the System Preferences application.
    3. The Network pane of the System Preferences application displays a Location pop-up menu near the top of its window.In this Location pop-up menu, select a location that includes the network interface of interest.
      For Mac OS X 10.4: You can verify that a network interface (port) is a member of a location by selecting that location, then in the Show pop-up menu, selecting Network Port Configurations. Verify that network interface of interest appears in the port list, and is turned "on" (its checkbox is checked).
      For Mac OX X 10.5 - 10.7: You can verify that a network interface (port) is a member of a location by selecting that location, then verifying that the network interface of interest appears in the network ports list on the left side of the window. Verify that the interface's status (which appears in grey just below the name of the interface) is anything other than "Inactive."
    4. If you made any changes in this window, click the Apply button in the lower right corner of the window.
    5. If you made any changes in the Network pane in System Preferences that you won't want to retain, make a note of them now, so you can undo them later.
    6. Once you've verified that the network interface you're interested in is part of the current location and is turned "on" (in 10.4), or is anything except "inactive (in 10.5 - 10.7), you can selectQuit System Preferences from the File menu.
  2. In Mac OS X 10.4 - 10.6, launch the System Profiler application. In Mac OS X 10.7, launch the System Information application.This program is normally located in the Utilities folder, which in turn is located in the Applications folder.
  3. In the Contents pane on the left, select Network.
  4. Displayed in the upper-right pane is a list of each of the Mac's network interfaces that are part of the current network location and are turned "on" (in 10.4), or anything except "inactive" (in 10.5 - 10.7). (In 10.6 - 10.7, these are entitled "Active Services".)In this upper-right pane, select the item for the Ethernet or Wireless (a.k.a "AirPort") interface in which you are interested.
  5. Displayed in the lower-right pane is information about the selected network interface.Each interface's hardware address is the value labelled Ethernet addressMAC address, or Hardware (MAC) address This is true even if the device is actually a wireless interface. (It is not the item labelledRouterHardwareAddress.) Make a note of the value; this is the information you were seeking.
  6. Quit the System Profiler (in 10.4 - 10.6) application or the System Information (in 10.7) application.
  7. If earlier you changed any settings in the Network pane of System Preferences (e.g. to make a particular network interface active) and you wish to change it back, do so now.

Apple iPhone OS 3.1 - 3.2; iOS 4.0 - 5.0

To display your Apple iOS (or iPhone OS) device's Wireless hardware address:
  1. Open the Settings application.
  2. From the list of setting categories, select General.
  3. From the list of general settings, select About.
  4. The Wireless hardware address is the value labelled Wi-Fi Address.
  5. Leave the Settings application.

Android 2.2, 2.3

To display your Android device's Wireless hardware address:
  1. Open the Settings application.
  2. From the list of setting categories, select About phone. (This category might be named something else, for example, About tablet.)
  3. From the list of choices, select Hardware information. On some versions of Android, you may instead need to choose Status.
  4. The Wireless hardware address is the value labeled Wi-Fi MAC Address.
  5. Leave the Settings application.

Sun

When executed as root, the following command will show the hardware address for each Ethernet interface that is plumbed on the system:
# /usr/sbin/ifconfig -a

   lo0: flags=1000849 mtu 8232 index 1
           inet 127.0.0.1 netmask ff000000 
   hme0: flags=1000843 mtu 1500 index 2
           inet 192.168.1.2 netmask fffffc00 broadcast 192.168.1.0
           ether 8:0:20:4:5:6

Friday, October 14, 2011

RAID 0, RAID 1, RAID 5, RAID 10


RAID stands for Redundant Array of Inexpensive (Independent) Disks.
On most situations you will be using one of the following four levels of RAIDs.
  • RAID 0
  • RAID 1
  • RAID 5
  • RAID 10 (also known as RAID 1+0)
This article explains the main difference between these raid levels along with an easy to understand diagram.

In all the diagrams mentioned below:
  • A, B, C, D, E and F – represents blocks
  • p1, p2, and p3 – represents parity

RAID LEVEL 0


Following are the key points to remember for RAID level 0.
  • Minimum 2 disks.
  • Excellent performance ( as blocks are striped ).
  • No redundancy ( no mirror, no parity ).
  • Don’t use this for any critical system.

RAID LEVEL 1

Following are the key points to remember for RAID level 1.
  • Minimum 2 disks.
  • Good performance ( no striping. no parity ).
  • Excellent redundancy ( as blocks are mirrored ).

RAID LEVEL 5


Following are the key points to remember for RAID level 5.
  • Minimum 3 disks.
  • Good performance ( as blocks are striped ).
  • Good redundancy ( distributed parity ).
  • Best cost effective option providing both performance and redundancy. Use this for DB that is heavily read oriented. Write operations will be slow.

RAID LEVEL 10

Following are the key points to remember for RAID level 10.
  • Minimum 4 disks.
  • This is also called as “stripe of mirrors”
  • Excellent redundancy ( as blocks are mirrored )
  • Excellent performance ( as blocks are striped )
  • If you can afford the dollar, this is the BEST option for any mission critical applications (especially databases).

Monday, October 10, 2011

Detect and Avoid IP Address Conflicts

IPv4 address conflicts are a common cause of problems with DHCP. No two computers on the network can have the same unicast IP address. If a computer is assigned the same unicast IPv4 address as another, one or both of the computers might become disconnected from the network.

To better detect and avoid potential conflicts, you can enable IPv4 address conflict detection by following these steps:
1. In the DHCP console, expand the node for the server you want to work with, right-click IPv4, and then click Properties.
2. On the Advanced tab, set Conflict Detection Attempts to a value other than 0. The value you enter determines the number of times the DHCP server checks an IP address before leasing it to a client. The DHCP server checks IP addresses by sending a ping request over the network.

Real World Example: A unicast IPv4 address is a standard IP address for class A, B, and C networks. When a DHCP client requests a lease, a DHCP server checks its pool of available addresses and assigns the client a lease on an available IPv4 address. By default, the server checks only the list of current leases to determine whether an address is available. It doesn’t actually query the network to see whether an address is in use.

Unfortunately, in a busy network environment, an administrator might have assigned this IPv4 address to another computer or an offline computer might have been brought online with a lease that it believes hasn’t expired, even though the DHCP server believes the lease has expired. Either way, you have an address conflict that will cause problems on the network. To reduce these types of conflicts, set the conflict detection to a value greater than 0.


Friday, October 7, 2011

Use the Wbadmin Backup Command Line Utility in Windows Server 2008

Wbadmin is the command-line counterpart to Windows Server Backup. You use Wbadmin to manage all aspects of backup configuration that you would otherwise manage in Windows Server Backup. This means that you can typically use either tool to manage backup and recovery.

After you’ve installed the Backup Command-Line Tools feature, you can use Wbadmin to manage backup and recovery. Wbadmin is located in the %SystemRoot%\System32\ directory. As this directory is in your command path by default, you do not need to add this directory to your command path.


You can run Wbadmin by following these steps:
1. Click Start, click All Programs, and then click Accessories to open the Accessories menu.
2. Start an elevated command prompt by right-clicking Command Prompt and then selecting Run As Administrator.
3. In the Command Prompt window, enter the necessary command text or run a script that invokes Wbadmin.

Wbadmin has a number of associated commands:
DELETE SYSTEMSTATEBACKUP Deletes the system state backup or backups from a specified location.
DISABLE BACKUP Disables scheduled daily backups so that they no longer run.
ENABLE BACKUP Enables or modifies a scheduled daily backup.
GET DISKS Lists the disks that are currently online for the local computer. Disks are listed by manufacturer name, type, disk number, GUID, total space, used space, and associated volumes. GET ITEMS Lists items contained in a specified backup.
GET STATUS Reports the status of the currently running backup or recovery job.
GET VERSIONS List details about the available backups stored in a specific location, including the backup time and backup destination.
START BACKUP Starts a one-time backup using the specified parameters. If no parameters are passed and scheduled backups are enabled, the backup uses the settings for scheduled backups.
START RECOVERY Initiates a recovery of volumes, applications, or files using the specified parameters.
START SYSTEMSTATEBACKUP Starts a system state backup using the options specified.
START SYSTEMSTATERECOVERY Starts a system state recovery using the specified parameters.
STOP JOB Stops the currently running backup or recovery job. Stopped jobs cannot be restarted from where they were stopped.

When you are working with Wbadmin, you can get help on available commands:
1.To view a list of management commands, type wbadmin /? at the command prompt.
2.To view the syntax for a specific management command, type wbadmin Command /?, where Command is the name of the management command you want to examine, such as wbadmin stop job /?.

When you work with Wbadmin, you’ll find that just about every command accepts parameters and specific parameter values that qualify what you want to work with. To see more clearly how this works, consider the following syntax example:
wbadmin get versions [-backupTarget:{VolumeName | NetworkSharePath}]
[-machine:BackupMachineName]
The brackets tell you that –backupTarget and –machine are optional. Thus, you could type the following to get information on recoverable backups on the local computer:
wbadmin get versions
You could type the following to get information on recoverable backups for C:
wbadmin get versions -backuptarget:f:
Or you could type the following to get information on recoverable backups for C on Server96:
wbadmin get versions -backuptarget:f: -machine:server96
Many Wbadmin commands use the –backupTarget and –machine parameters. The backup target is the storage location you want to work with, and can be expressed as a local volume name (such as F:) or as a network share path, such as \\FileServer32\backups\Server85. The –machine parameter identifies the computer you want to work with for backup or recovery operations.

Reminders not popping up in Outlook 2007


Summary
After performing Windows updates and installing Microsoft KB number 2583910 for Outlook 2007 a warning appears stating:
There was a problem reading one or more of your reminders. Some reminders may not appear.
Details
This is similar to the problem encountered when Microsoft Office 2010 SP1 was released.
In order to resolve this, please uninstall Microsoft update KB2583910
Once that is uninstalled, please start outlook.exe with the option /cleanreminders turned on.