Gathering Information about Your Computers
Updated: January 27, 2010
Applies To: Windows Server 2008, Windows Server 2008 R2
One of the most valuable benefits of conducting an asset discovery project is the large amount of data that is obtained about the client and server computers on the network. When you start designing and planning your isolation zones, you must make decisions that require accurate information about the state of all hosts to ensure that they can use IPsec as planned.
Capture the following information from each computer:
Computer name. This name is the computer's NetBIOS or DNS name that identifies the computer on the network. Because a computer can have more than one media access control (MAC) or IP address, the computer's name is one of the criteria that can be used to determine uniqueness on the network. Because computer names can be duplicated under some circumstances, the uniqueness should not be considered absolute.
IP address for each network adapter. The IP address is the address that is used with the subnet mask to identify a host on the network. An IP address is not an effective way to identify an asset because it is often subject to change.
MAC address for each network adapter. The MAC address is a unique 48-bit address that is used to identify a network adapter. It can be used to help differentiate between different network adapters on the same device.
Operating system, service pack, and hotfix versions. The operating system version is a key factor in determining the ability of a host to communicate by using IPsec. It is also important to track the current state of service packs and updates that might be installed, because these are often used to determine that minimum security standards have been met.
Domain membership. This information is used to determine whether a computer can obtain IPsec policy from Active Directory or whether it must use a local IPsec policy.
Physical location. This information is just the location of the device in your organization. It can be used to determine whether a device can participate in a specific isolation group based on its location or the location of the devices that it communicates with regularly.
Hardware type or role. Some tools that perform host discovery can provide this information by querying the hardware information and running applications to determine its type, such as server, workstation, or portable computer. You can use this information to determine the appropriate IPsec policy to assign, whether a specific computer can participate in isolation, and in which isolation group to include the computer.
After collecting all this information and consolidating it into a database, perform regular discovery efforts periodically to keep the information current. You need the most complete and up-to-date picture of the managed hosts on their networks to create a design that matches your organization's requirements.
You can use various methods to gather data from the hosts on the network. These methods range from high-end, fully automated systems to completely manual data collection. Generally, the use of automated methods to gather data is preferred over manual methods for reasons of speed and accuracy.
Using an automated auditing network management system such as Microsoft System Center Configuration Manager (formerly known as Systems Management Server) provides valuable information about the current state of the IT infrastructure.
For more information about how System Center Configuration Manager 2007 can help perform automated information gathering, see http://go.microsoft.com/fwlink/?linkid=110412.
The biggest difference between manual discovery methods and automated methods is time.
You can use the Windows Script Host (WSH), VBScript, and Windows Management Instrumentation (WMI) to create a script file that can collect the system configuration information. VBScript and WMI are built-in to Windows 2000, Windows XP, Windows Server 2003, Windows 7, Windows Vista, Windows Server 2008, and Windows Server 2008 R2. In addition, PowerShell is available as a free download for computers that run Windows XP, Windows Server 2003, or later versions. Starting with Windows Server 2008, PowerShell is included with the operating system. For more information, see “Scripting with Windows Powershell” (http://go.microsoft.com/fwlink/?linkid=110413).
Whether you use an automatic, manual, or hybrid option to gather the information, one of the biggest issues that can cause problems to the design is capturing the changes between the original inventory scan and the point at which the implementation is ready to start. After the first scan has been completed, make support staff aware that all additional changes must be recorded and the updates noted in the inventory.
This inventory will be critical for planning and implementing your Windows Firewall with Advanced Security design.