Windows Command Line Utility

ipconfig is a commmand line utility available on all versions of Microsoft Windows starting with Windows NT. ipconfig is designed to be run from the Windows command prompt. This utility allows you to get the IP address information of a Windows computer. It also allows some control over active TCP/IP connections. ipconfig is an alternative to the older ‘winipcfg’ utility.

ipconfig Usage

From the command prompt, type ‘ipconfig’ to run the utility with default options. The output of the default command contains the IP address, network mask and gateway for all physical and virtual network adapters.

‘ipconfig’ supports several command line options as described below. The command “ipconfig /?” displays the set of available options.

ipconfig /all

This option displays the same IP addressing information for each adapter as the default option. Additionally, it displays DNS and WINS settings for each adapter.

ipconfig /release

This option terminates any active TCP/IP connections on all network adapters and releases those IP addresses for use by other applications. ‘ipconfig /release” can be used with specific Windows connection names. In this case, the command will affect only the specified connections and not all. The command accepts either full connection names or wildcard names. Examples:

ipconfig /release “Local Area Connection 1″
ipconfig /release *Local*

ipconfig /renew

This option re-establishes TCP/IP connections on all network adapters. As with the release option, ipconfig /renew takes an optional connection name specifier.

Both /renew and /release options only work on clients configured for dynamic (DHCP) addressing.

Note: The remaining options below are only available on Windows 2000 and newer versions of Windows.

ipconfig /showclassid, ipconfig /setclassid

These options manage DHCP class identifiers. DHCP classes can be defined by administrators on a DHCP server to apply different network settings to different types of clients. This is an advanced feature of DHCP typically used in business networks, not home networks.

ipconfig /displaydns, ipconfig /flushdns

These options access a local DNS cache that Windows maintains. The /displaydns option prints the contents of the cache, and the /flushdns option erases the contents.

This DNS cache contains a list of remote server names and the IP addresses (if any) they correspond to. Entries in this cache come from DNS lookups that happen when attempting to visit Web sites, named FTP servers, and other remote hosts. Windows uses this cache to improve the performance of Internet Explorer and other Web-based applications.

In home networking, these DNS options are sometimes useful for advanced troubleshooting. If the information in your DNS cache becomes corrupted or outdated, you could face difficulty accessing certain sites on the Internet. Consider these two scenarios:

• The IP address of a Web site, email server or other server changes (rare occurence). The name and address of this site normally stay in your cache for 24 hours after your last visit. You may need to clear your cache to access the server sooner.
• A Web site or other server was offline when you last visited it (hopefully a rare occurence) but since has come back online. The cache will normally keep a record that the server is offline for 5 minutes afer your last visit. You may need to clear your cache to access the server sooner.

ipconfig /registerdns

Similar to the above options, this option updates DNS settings on the Windows computer. Instead of merely accessing the local DNS cache, however, this option initiates communication with both the DNS server (and the DHCP server) to re-register with them.

This option is useful in troubleshooting problems involving connection with the Internet service provider, such as failure to obtain a dynamic IP address or failure to connect to the ISP DNS server.

Like the /release and /renew options, /registerdns optionally takes the name(s) of specific adapters to update. If no name parameter is specified, /registerdns updates all adapters.

Google’s Chrome accounts only for about 4 percent of browser usage worldwide, but in 2009, it exerted outsized influence.

Google launched the open-source browser in 2008, prompting many to ask why anyone needed another after Microsoft’s Internet Explorer, Mozilla’s Firefox, and Apple’s Safari. But over the course of 2009, Google answered that question: with Chrome, the company wants not just to speed up the Web but to rebuild its foundations.

Chrome started out as one of Google’s efforts to accelerate the Web–launching faster, loading pages faster, and running Web-based JavaScript programs faster. Google’s argument: a faster Web experience means people will spend more time online, do more things, and, naturally, click more Google search ads.

JavaScript was the first step, showcased in Google’s processing-intensive Chrome Experiments site. It’s lost on no one that Google Docs and Gmail are written in JavaScript, so faster performance helps expand their capabilities.

Next came integration with Chrome and two technologies for accelerating Web applications, Google’s O3D for 3D graphics, and Native Client software for accelerating general-purpose processing.

But the most ambitious change came with July’s announcement of the open-source Chrome OS operating system. It uses Linux under the covers, but Chrome OS applications all run in the browser. That design today has serious practical limitations, so it’s fitting the first incarnation of Chrome OS, due in 2010, is for “companion” Netbooks rather than full-fledged replacement PCs. Google released the rough Chrome OS source code in November.

On a more down-to-earth note, by year’s end, Google had released a beta version of Chrome for Mac and Linux, not just Windows, and added a long-awaited extensions system.

Many Chrome ambitions are still far from any practical reality, but the browser had effects. One: Mozilla programmers have improved launch speed in the Firefox 3.6 beta.

Although Chrome stole some hearts among the techies who historically embraced Firefox, Mozilla’s browser was hardly pushed aside. Indeed, Firefox usage crept steadily up to about 25 percent worldwide over 2009. That’s a large enough population to make Mozilla’s effort to “upgrade the Web” more than posturing.

Mozilla is aggressively adding new features to Firefox, and a host arrived with Firefox 3.5 in June, notably the ability to embed video directly into Web pages without requiring a plug-in such as Adobe Systems’ Flash. HTML5 video remains hobbled by differences in opinion over the best video format to use, though. Ultimately, browser companies want to make the Web a foundation for applications, not just static sites, and the work includes interfaces for file handling, multitasking, Webcams, geolocation, and WebGL for 3D graphics.

Some of these improvements are spreading to multiple browsers through development of version 5 of the Hypertext Markup Language. Even Microsoft, whose Internet Explorer is derided as a laggard by techies and Web developers, climbed aboard with direct participation in HTML5 standardization work.

Those plans advanced in July when the World Wide Web Consortium threw its full weight behind HTML5 rather than the comparatively unsuccessful alternative, XHTML 2.0.

Microsoft and Apple, who enjoy the privilege of packaging their browsers in their operating system, released major new versions, Internet Explorer 8 and Safari 4, respectively. Safari took the 64-bit leap, and Apple boasted of its big JavaScript speed boost. IE 8 brought a number of user-interface refinements, but notably, Microsoft lists better security and privacy as primary features.

Attention now is shifting toward IE 9, though, which Microsoft previewed in December. Hardware acceleration dramatically speeds up some elements of its display, and the new version will comply better with Web standards. Microsoft hasn’t announced a ship date for the new version, but it’s clear the company is feeling more comfortable with its re-engagement in the browser wars.

The semiconductor industry is set to post a revenue drop of $29 billion for this year, according to research firm Gartner.

Worldwide revenue for 2009 totaled $226 billion, down 11.4 percent from 2008, the company said in a research report published on Thursday. It marks only the sixth time in 25 years that the semiconductor industry has posted an annual decline, and is the first time it has seen a drop for two years in a row, according to Gartner.

While revenue fell sharply at the beginning of 2009, carrying on a fall prompted by the economic recession the year before, it began to rise again in the spring, according to the report.