June 20th, 2010 -- Posted in Cool Items |
A terrific value-a full-size book plus video demonstrations of key Windows 7 tasks Windows 7 is Microsoft’s much-anticipated new release of the operating system that powers nearly 90% of the world’s computers. This two-for-one package provides the step-by-step guidance that will get you up and running with all the exciting new features. This bundle includes the complete Windows 7 For Dummies book plus a DVD with two hours of video training. Featuring the expert advice you get in the book, the DVD shows you how to accomplish various Windows tasks and displays the screens you’ll see as you proceed. A two-for-one value – the full-size Windows 7 For Dummies book plus two hours of video training on DVD Windows 7 has new features, an interface with more graphical elements, better interactivitiy with other devices, and faster speed Whether you’re new to computers or just to Windows 7, this handy package provides a simple, easy-to-use guide plus video i (more…)
June 18th, 2010 -- Posted in Cool Items |
Amazon.com
Windows 7 Ultimate is the most versatile and powerful edition of Windows 7. It combines remarkable ease-of-use with the entertainment features of Home Premium and the business capabilities of Professional, including the ability to run many Windows XP productivity programs in Windows XP Mode. For added security, you can encrypt your data with BitLocker and BitLocker To Go. And for extra flexibility, you can work in any of 35 languages. Get it all with Windows 7 Ultimate. More work, more play, and more of everything in between. Click to enlarge. Manage lots of open programs, documents, and browser windows easily with thumbnail and full-screen previews of open windows. Click to enlarge. With Snap you can arrange two windows side-by-side just by dragging them to opposite sides of your screen. Click to enlarge. Open files you use regularly in just two clicks with Jump Lists on the improved taskbar. Des (more…)
November 10th, 2009 -- Posted in Other |
Overview
The process of troubleshooting your network if it has wireless components is somewhat more complex than wired infrastructure. In fact you must troubleshoot both wired and wireless infrastructure to determine the problem. The methodology of starting with cabling from the client and working through the OSI model to the application layer is effective. The wireless client traffic doesn’t see any cabling until there has been association with the access point. In essence there is a data link between wireless client and access point. With that established there is data link traffic between access point and wired network switch.
The wired client has a Cat 5 cable plugged into the desktop that terminates at a wired switch. All clients associating at a specific access point now share a single Cat 5 cable run from access point to switch. That makes troubleshooting easier since cabling is a source of a lot of network problems, however any problems with that cable affects all clients. It is important to minimize the number of access point clients for maximum performance. Commercial network implementations average 10 – 24 clients per access point.
The key with troubleshooting is to determine what has changed. Sometimes it is hardware that isn’t working or some change made such as new software, configured equipment or additional employees stressing the network. It could be a specific issue or several problems. Start with the client adapter, determine the specific symptoms and go from there.
The following is a series of questions that can used as a guideline during the troubleshooting process:
1. Can the wireless client associate with any access point?
2. Can you ping the switch IP address?
3. Can you ping the router?
4. Can you ping the DHCP server?
5. Does the client obtain an IP address?
6. Is the WAN circuit available?
7. Has new software been installed on the client?
8. Do all clients experience the problem?
9. Is it random or a specific pattern?
10. Is it server specific or application specific?
11. Is the DNS server IP address setting correct?
12. Is there a firewall that is filtering traffic?
TOOLS:
a) Wireless client software shows status information such as access point association, DHCP enabled, IP address, default gateway, DNS server address.
b) Windows control panel shows wireless adapter settings, firewall configuration etc.
c) Ping will verify that network routing is working.
d) Network packet sniffers examine packet information such as protocols, filtered programs or errors with applications.
e) Spectrum analyzers detect frequency interference and possible sources.
COMMON WIRELESS PROBLEMS:
Wireless Client Settings
• Upgrade the manufacturer client adapter driver.
• Implement current Windows operating system service pack.
• Examine client data rate, transmit power, preamble, roaming decision, WPA settings.
• Confirm shared keys if implemented aren’t mismatched between client and AP.
• Examine IP address settings. DHCP will send specific settings to each client. Those clients without DHCP must configure IP address, subnet mask, default gateway and DNS server IP address.
• The client SSID name configured should match what is configured at the AP.
Access Point
• Confirm the APs have the recommended IOS version with the specific feature set.
• Examine AP mounting and modify if necessary using the installation instructions.
• Delete any configured loopback addresses.
• Configure transmit power setting and decrease when channel interference occurs.
• Mixed 802.11b/g environments must configure each AP with 802.11b basic data rates.
• Configure data rate and duplex settings to match between AP and switch.
Design
• Configure data rate and duplex setting to match between wireless bridges.
• Standard Cat 5 UTP cable should be a maximum of 328 feet between AP and switch.
• Distance from the wireless client to access point should not exceed the specified range.
• Maximum number of clients per access point should not exceed 17 – 24.
• Don’t assign channel overlap between neighbor APs.
• Configure spanning tree protocol at root bridges
• Configure non overlapping channels of 1, 6 and 11 at 802.11b and 802.11g APs.
• Don’t configure multiple root bridges on the same WLAN
• Implement the most current version of Windows Server, IAS RADIUS Server or Cisco ACS
• RF interference will occur in an unlicensed band. Minimize sources where possible.
Cisco Wireless Network Design Guide available at amazon.com and eBookmall.com
Shaun Hummel is an author of various technical books and has a web site focused on information technology job search solutions and certifications.
http://www.networkjobsolutions.com
Shaun Hummel, CCNP, is a Senior Network Engineer with 11 years experience in enterprise network planning, design, and implementation. He has worked for various private and public companies in Canada and the United States improving infrastructure, security, and management. He has written Network Planning and Design Guide, Cisco Wireless Network Design Guide and Network Assessment Guide.
www.networkjobsolutions.com
