How to use commands to clear information in the DNS cache

We can use commands at the command prompt to clear the information in the DNS client cache. After the client executes the "Ipconfig/flushdns" command, the "ping" command appears after the letter is prompted to resolve the problem.

It is worth noting that, in the administrative tools, open the Services tool and find the DNS client entry, which does not cache DNS query information on the client after the service is stopped, so that modifications made on the DNS server can be reflected immediately when the client requery.

When there is a problem with domain name resolution, it is possible that the DNS server has updated the IP of this domain name, and the information stored in the local DNS cache does not correspond to the problem of domain name resolution, it is necessary to update the local DNS local cache, simply clear the local DNS local cache on the line.

1, in the operation of the input cmd, and then input Ipconfig/flushdns can be.

2. The DNS Client service in the system service is stopped and DNS query information can not be stored locally.

3, close IE, and then clear the history of the record or restart machine.

Three methods can immediately resolve the domain name correctly. Sharing ODBC connections between users 2000 supports Open Database Connectivity (ODBC), a standard mechanism developed by Microsoft, which enables customers to access databases created by various database management systems without having to install a DBMS locally.

For example, you could create an ODBC connection on a single server that would allow access to a product database from the Web. Web pages with IIS as the host system can contain the necessary calls to access ODBC connections and underlying data.

2000 supports three ODBC data source names (DSNs): Systems, users, and files. 2000 of the system and user DSN are stored in the registry. A file DSN is a file with a suffix named. dsn.

A common use of File DSNs is to provide a database connection to a local application, such as Excel or Access. The advantage of using a folder DSN is that you can easily share it among users, either through a network share or by copying DSN files to each user's computer.

To share a file DSN between users, use the data source applet under the Administration Tools applet in Control Panel to create the DSN first, and then place the DSN where a user can access it. The user must add the DSN folder path to their corresponding application settings.

For example, if the user uses Excel, select the data import external data to create a new database query. In the Select Data Source dialog box, click Options, enter the path to the Shared DSN folder, and then click Do Close the dialog box. The DSN can then be used by other users in the application.

Using scavenging to clear DNS

The 2000 DNS service supports the scavenging feature, which helps you to ensure that DNS records managed by the service remain updated. Scavenging is important If you use dynamic DNS to automatically register their hostname after the customer's IP address has changed, as much as the client automatically obtains the IP address via DHCP.

Over time, client host records in a zone may become obsolete and scavenging delete these records. Deleting records can improve DNS server and zone transport performance, and it also guarantees that host records are not old record conflicts.

You can configure scavenging by using an area's properties. Open the DNS console, right-click Zone and select Properties. On the General tab, click Aging to open the Zone Aging/scavenging Properties dialog box. Use the Drop-down list box to set the refresh Interval and Non-refresh Interval, select the scavenge stale Resource Records check box, and click OK to close the two dialog boxes. You can also configure scavenging for the zone as a whole by editing the server's properties, rather than a single area. In the DNS console, right-click the server and select Set aging/scavenging for all Zones. The dialog box that pops up is the same as the dialog box that configures a single area.

Delegate a policy Group object

Using Ipconfig to observe and manage DNS resolution caching

The DNS client on the Professional platform resolves the host name to an IP address, as is the case with other operating platforms. DNS resolution requires support for Web browsers, as well as for mail services and other applications that rely on host names rather than IP addresses.

DNS resolution stores DNS query results, including affirmative queries, and of course includes negative queries (parsing failed queries).

Each DNS record has a time to live (TTL) value that determines when the record is refreshed and then replaced by other queries. Before the TTL arrives, parsing returns the results of the query in the cache without starting a new query.

When you want to troubleshoot connection and DNS issues, it is necessary to empty the DNS cache and force a new resolution of a host name. You can use the ipconfig console command to observe the cache capacity and empty the cache.

The following commands show the capacity of the cache and send the result to the more instruction, which displays the results once in one page: Ipconfig/displaydns more

Use this command to empty the cache: Ipconfig/flushdns

Delegate a policy Group object

As the network expands, especially when it comes to managing policy groups across different departments or regions, you will find it increasingly difficult to manage servers and networks. The delegation control of the Policy Group control object (GPOs) can help to simplify your management. Delegated administrators are able to manage policy groups with special organizational units (OUs) or domains as needed.

Delegate GPO management to set the GPO Access control table to control user read/write access, the following steps are set:

1. Open Active Directory user and computer console

2. Click the right mouse button in the OU connected to the GPO to expand the domain and select attributes;

3. Click on the Strategy Group label, select GPO, and then click Properties;

4. Click on the safety label, add the group or user who has been entrusted with the GPO, and choose to allow read and write operations;

5. Click OK to close the GPO property bar, and then press OK to close the property bar of the OU;