Monday, December 30, 2013

Networking: 802.11 WiFi Standards (Updated)

Are you confused by all the 802.11 WiFi "alphabet soup of letter name" standards, such as 802.11a, 802.11b, 802.11g, etc? Currently 802.11n  is the most popular standard, and its backwards compatible with 802.11b, and 802.11g.

Here is a brief breakdown of the different 802.11 standards; including: speed, frequency, and the date it was ratified as a standard:
  • 802.11: up to 2Mbps, uses the 2.4GHz frequency (Finalized: 1997)
  • 802.11b: up to 11Mbps, uses the 2.4GHz frequency (Finalized: 7/1999)
  • 802.11a: up to 54Mbps, uses the 5GHz frequency (Finalized: 7/1999)
  • 802.11g: up to 54Mbps, uses the 2.4GHz frequency (Finalized: 6/2003)
  • 802.11n: up to 150Mbps+, uses the 2.4Ghz and 5GHz frequency (Finalized: 10/2009)
    • Utilizes MIMO (Multiple-Input Multiple-Output), uses multiple transmitters and receivers antennas to allow for increased data throughput.
    • Some Wi-Fi cards and routers can support speeds of 300Mbps when utilizing a feature called 'channel bonding' (if its supported in the networking equipment) and not running into interference from other nearby wireless networks.
  • 802.11ac: up to 866Mbps+, uses the 5GHz frequency (Still in draft)
For more information see the following Wikipedia article.

From: Wikipedia
Notes:
  • All 802.11 Wi-Fi hotspots only can run as fast as the slowest device on the network.  For example, if you have a 802.11n wireless network with 5 people communicating at 150Mbps. Then if someone brings 802.11b device on the network the Wireless Access Point will slow down to 11Mbps to support the slower device. 
  • 2.4GHz equipment can incur interference from microwave ovens, cordless phones, and other appliances using the same radio signal frequency range.
  • The higher frequency 5GHz equipment signals has more difficulty penetrating walls and other obstructions.

Monday, December 23, 2013

Windows 8: TCP/IP Addressing (Static and Dynamic)

In Windows, you can have one of two types of IP addresses: dynamic or static. Dynamic IP addresses are temporarily assigned to a network device when their requested, and is generally done during the boot process. The network service that assigns dynamic IP addresses is known as DHCP. While static IP addresses have to be manually assigned to a device by a systems administrator, and are meant to be changed infrequently.

Dynamic IP addresses are the most common method of assigning an IP address to a network based device (such as a computer, printer, etc) because it reduces the network administration overhead. Today's office and work force are in a constant state of flux. People with mobile devices (such as tablets, smartphones, and laptops) will move from location to location, even desktop users can get moved around within a company on a semi-regular basis.
Note: If a Windows client makes a DHCP request for an IP address and doesn't get a reply in a timely manor, then it will switch to using Automatic Private IP Addressing (APIPA). APIPA is a private IP address range (169.254.0.0 to 169.254.255.255) that allows devices on a network using this address range to communicate with themselves. To configure this service, click on the Alternate Configuration tab in the Internet Protocol (TCP/IP) dialog.
If all devices used a static IP address, it would cause a network administration nightmare, they would all have to be changed every time a device was moved.  Most static IP addresses are assigned to servers or network based devices like routers or DNS servers. These devices need a static IP address because other devices on the network depend on knowing how to contact them.

To configure the TCP/IP addressing (dynamic or static) in Windows, follow the instructions below:
  • From the Start screen, type Network and click Settings on the right.  Click the Network and Sharing Center icon.  In the left pane, click the Change adapter settings link.
  • Right-click the active network connection (note: this selection can change between systems depending on the equipment that is installed), and select Properties.
  • Select Internet Protocol Version 4 (TCP/IPv4) [or Internet Protocol Version 6 (TCP/IPv6) depending on how your network is configured] and the press the Properties button.
From here you can select one of two options, Obtain an IP address automatically (dynamic) or Use the following IP address (static). If you're using a static IP address you need to know the following information: unique IP address, subnet mask for the network, IP address of the default gateway, and the IP addresses of the primary and secondary DNS servers. When you're done press the OK button twice.

Networking tips:

  • To find the TCP/IP address of the local computer, from the command prompt type: IPCONFIG /ALL.
  • To request a new DHCP address, from an administrator command prompt type: IPCONFIG /RELEASE and then type: IPCONFIG /RENEW 

Monday, December 09, 2013

Windows 8: File Path Name Tricks

Some windows commands require that you use the full path name of a file, which can be quite long depending on how deep it's in a folder structure.

Below are some tricks to avoid typing this information:
  • Hold down the Shift while right-clicking the file or folder and select Copy as path.  This will copy the objects path to the clipboard.
  • Drag and drop the file from the desktop or File Explorer into the command prompt window, or the Run... command (WinKey + R) Open field.  From here you can select the text and copy it to the clipboard.
Bonus tip: To open a command prompt at a specific folder in the folder structure, just right-click it and select Open command window here in the pop-up context menu.

Monday, December 02, 2013

Windows 8: File Explorer Keyboard Shortcuts

Most of us use Window's built-in File Explorer application (formerly known as the Windows Explorer) to manage files, folders and drives that are accessible by the local computer.

If you prefer using the keyboard to control an application, here are some of the better keyboard shortcuts to know for the File Explorer.
  • Ctrl + F: Open up the search pane. 
    • Build a complex search query using the controls in the pane to find specific files.
  • Alt + Up Arrow (or backspace): Go up a folder.
  • Alt + Right Arrow: Go forward (takes you back into your folder browsing history)
  • Alt + Left Arrow: Go back (takes you back into your folder browsing history)
  • Alt + D: Focus the address bar and select the current path.
  • Alt + P: Shows the Preview pane
  • Alt + Shift + P: Shows the Details pane
  • Alt + Enter: Properties of the selected file
  • Ctrl + Mouse wheel: changes the folder view type.
  • Ctrl + Shift + N: Creates a new folder at the current location
  • Ctrl + F1: Opens or closes the ribbon at the top of the window 
  • F4: Opens dropdown menu in the address bar.
  • F11: Puts the File Explorer into full-screen mode.
Note: The Windows File Explore tracks the folder browsing history, similar to the way Internet Explorer's tracks your browsing history. Every folder or network path you visit is remembered, you can then use the Alt+Left or Right arrow to move through the folder location history that were previously visited.