Richard n Williams wrote:


All computers have clocks of course although the real time chips (RTC) that inhabit most PC’s are not the most accurate of timepieces and are prone to drift.

This may not matter much to the average home user although when it comes to time sensitive applications this inaccuracy can be at best annoying (an email arriving before its been sent) or at worst leaving your machine open to security threats.

A universal time (UTC) does exist and allows the global industry to communicate and trade even across time zones. UTC was developed to ensure that everybody used the same time reference, preventing problems with time sensitive transactions such as on the stock exchange.

Windows Vista has an inbuilt time synchronisation facility already installed called Windows Time and it is pretty easy to setup and to synchronise a machine with UTC over the Internet. This will ensure that the clock on your computer is accurate to UTC time and is constantly updated to ensure the time does not drift.

To synchronise your Windows Vista machine to an Internet UTC source simply follow these instructions:

1. Right click the clock in the system tray.

2. Click adjust time and date.

3. Click the Internet time tab.

4. Click change settings.

5. If you are prompted for a password or for confirmation, type the password, or click Continue.

6. Select the server you want to use (such as windows.time)

7. Click the Update now button.

8. Click Ok twice.

If problems occur then another method of synchronising your computer is possible via the command prompt by running w32tm / resync. This should activate the windows time service.

Note: Microsoft and other operating system manufacturers recommend that an external hardware source should be used to synchronise a computers clock as Internet time servers can not be authenticated leaving systems vulnerable to security threats.

There are specialist time servers that connect to a UTC source using either the GPS network or a specialist radio transmission. These servers use NTP (Network Time Protocol) to synchronise machines on a network to one UTC source and are easily installed and relatively inexpensive.

Window Vista also has a facility to add extra clocks to the system tray. This allows different times from different time zones to be displayed on the computer. If the clock has been synchronised with a UTC source then all these clock will present UTC time converted to whatever time zone is required.

To add additional clocks simply follow these instructions:

Choose change date and time settings.

1. Left click the clock and click Additional Clocks tab.

4. Put a check mark in Show this Clock.

5. Select the time zone.

6. Enter a name for your new clock.

7. Click apply, then when you click on the Clock icon you’ll see your new clocks.

arun wrote:


Network Diagnostic Tools in Windows Vista

In the Network Sharing Center there is a Diagnose and Repair link that will scan your system for network issues. This diagnostic pings the remote host. If it is not found, you have the option to reset the network adapter Local Area Connection.

In addition to the automated Network Diagnostics interface, several tools are included with Windows Vista that can be used to test network components and connectivity.

Basic Tools

The following tools are fundamental in connectivity and name resolution troubleshooting. In addition, they are useful when troubleshooting failures with applications that communicate on the network or Internet.

Ipconfig

The Ipconfig command line tool displays all current TCP/IP network configuration values. Used without parameters, the ipconfig command displays the IP address, subnet mask, and default gateway for all adapters. In addition, you can use the following commands:

ipconfig /all – If you want to see more detailed information on the configuration for all interfaces on the computer, use this command.

ipconfig /release – This command releases any DHCP addresses assigned to interfaces on the computer. You can typically use it before the next command.

ipconfig /renew – This command causes the DHCP client service to request network addresses for all network connections. It is useful when you encounter connectivity problems and suspect a bad address. It is also used when troubleshooting name resolution failures to ensure the interface has the correct DNS server addresses assigned.

ipconfig /flushdns – This command clears the local DNS resolver cache. When you connect to machines by name, the DNS client software on the computer stores names and IP addresses as they are resolved. This is so that the name can be resolved without sending a repeat request to the DNS server. If a remote computer’s IP address changes, outdated information in this cache can cause connections by name to fail. Run this command on the local machine to clear the cache.

Ping

The ping command verifies IP-level connectivity to another TCP/IP computer by sending ICMP Echo Request messages. The receipt of corresponding Echo Reply messages is displayed along with round-trip times.

Ping is the primary TCP/IP command used to troubleshoot connectivity, reachability, and name resolution.

Because firewalls typically block ICMP traffic, ping does not receive a response from a system with a firewall configured. Check the firewall settings to ensure Ping or ICMP Echo is enabled while you are troubleshooting.

Tracert

The Trace Route (Tracert.exe) command determines the path taken to a destination by sending ICMP Echo Request messages to the destination with incrementally increasing Time to Live (TTL) field values. The path displayed is the list of near-side router interfaces of the routers in the path between a source host and a destination. The near-side interface is the interface of the router closest to the sending host in the path.

This command is useful for troubleshooting connectivity failures when you can ping the default gateway but cannot ping Internet servers. Such a situation can indicate a failure in the routing from the client machine to the Internet.

Running Tracert returns data on the failure indicating which hop in the routing is dropping the traffic. When used for Internet connectivity troubleshooting, the data gathered is often used to work with the ISP to resolve such routing issues. The output should identify the router at which the problem occurs.

For more details, please refer to www.wintechhelp.com