缓存清除DNS本地缓存

清除DNS本地缓存

Clear DNS local cache

Windows 2000 automatically starts the DNS Client service, whichprovides the Client' s name resolution and caching service, andthe user' s DNS query results are cached locally. Whenconfiguring the DNS server, you will often have some wrongactions if you don' t master this principle well.

We can use the command prompt to remove information from theDNS client cache. After the client executes the

"Ipconf ig/flushdns" command, the "pingwww. jgx. com" command isthen executed to resolve the problem.

Worthy of our attention is that to open the "service" in the"management tools" tools, find the DNS Client, stop the servicein the Client won't caching DNS query information, such changeson the DNS server on the Client side to query immediatelyreflected.

When there is something wrong with the domain name resolution,can be updated this domain DNS server IP, and with the localDNS cache of information stored in the corresponding, causingthe DNS has a problem, just need to update the local local DNScache, simply remove the local local DNS cache.

Enter CMD at run time and enter ipconfig/flushdns.

Stop the DNS CLIENT service in the system service and not storethe DNS query information locally.

Shut off IE and clear the history or restart machine.All three methods can immediately resolve the domain namecorrectly.

Share the ODBC connection between users

Windows 2000 support open database connectivity (ODBC) , astandard mechanism developed by Microsoft, it can make theclients need not locally installed DBMS can access databasecreated by various database management system.

For example, you can create an ODBC connection on a server toaccess a product database from the Web. The Web page, which ishosted by IIS, can contain the necessary calls to access theODBC connection and the underlying data.

Windows 2000 supports three ODBC data source names (DSN) :systems, users, and files. Windows 2000' s system and user DSNare stored intheregistry. The fileDSN is afile witha suffixcalled.dsn.

The general usage of a file DSN is to provide a databaseconnection to a local application, such as Excel or Access. Theadvantage of using the folder DSN is that you can easily shareit between users, either by sharing or copying DSN files ontoeach user.

To share files between user DSN, use the management tool incontrol panel applet, the first to create a DSN data sourcesmall program, and then put the DSN in where a user can access.

The user must add the DSN folder path to their correspondingapplication Settings.

For example, if the user USES Excel, select data | to importexternal data | to create a new database query. In the selectdata source dialog box, click the option, enter the path to theShared DSN folder, and then click to actually close the dialogbox. The DSN can then be used by other users in the application.Using scavenging removal of DNS

The DNS service for Windows 2000 supports the scavengingfeature, which helps you to keep the DNS records from servicemanagement up to date. If you use a dynamic DNS client IP addresschanges automatically register their host name, scavenging isquite important, this kind of situation happened with thecustomer to obtain IP address automatically by the DHCP.Over time, the customer host records in one area may be obsolete,and scavenging deletes these records. The deletion recordimproves the DNS server and the region transport performance,and it also ensures that the host record is not an old recordconf lict.

You can conf igure scavenging through an area property. Open theDNS console, right-click the Zone and select Properties. In theGeneral TAB,

ClickAging to open the Zone Aging/Scavenging Properties dialog.Use the drop-down list box to set Refresh Interval andnon-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 region as a whole byediting the server' s properties, rather than configuring it fora single area. In the DNS console, right-click the server andselect Set Aging/Scavenging For All Zones. The pop-up dialogbox is the same as the dialog that configures a single area.Delegate a policy group object

Use Ipconfig to observe and manage DNS resolution cachingThe DNS customer on the Windows 2000 Professional platformparses the host name to the IP address, which is the same asany other Windows platform. DNS resolution requires support forWeb browsers, as well as for mail services and otherapplications that rely on hostnames instead of relying on IPaddresses.

Windows' s DNS resolution stores the DNS query results,including the positive query, and, of course, the negativequery (parsing the failed query) .

Each DNS record has a lifetime (TTL) value, which determineswhen the record is refreshed and replaced by other queries.Before TTL arrives, Windows parsing returns the query resultsin the cache without starting a new query.

It is necessary to clear the DNS cache and force Windows to makea new parsing of a host name when you have to solve the problemof connecting and DNS. You can use the IPConfig console command

to observe the cache capacity and empty the cache.

The cache can be displayed by the following command, and theresult is sent to the More command, which is shown in one pagein a single page:

Ipconfig/displaydns | more

Use this command to clear the cache:

Ipconfig/f lushdns

Delegate a policy group object

Along with the expansion of the network, especially in needacross different departments or regional policy groupmanagement when you will find that the server and networkmanagement is becoming more and more difficult. The delegatecontrol of the policy group control object (GPOs) can help yousimplify your administration. A delegated administrator canmanage policy groups with special organizations (Ous) ordomains as needed.

The GPO administration sets GPO access control table to controlthe user' s read/write access, which is the following:Open the active directory user and the computer consoleRight-click the OU that connects to GPO, right-click, expandthe domain, select the properties;

Click on the policy group label, select GPO, and then clickproperties;

Click on the security label, add the group or user that isauthorized to GPO, and choose to allow read and writeoperations.

Click on the confirmation key, close the GPO properties bar,and then press the key to close the properties bar of the OU.Because of the rampant spread of the APR virus, it has beenplagued by a loss of thread in the LAN, and has had to use WINDOWSto repair local connections. It is the steps

Remove the ARP cache and use the arp-d * instead

Clear NETBT, but use nbtstat -r instead

3. Remove the DNS cache

Registration with DNS may be replaced by ipconfig/flushdnsWhen the third step is done, the prompt "clears the DNS cachefailure", and immediately baidu answers the question, thesolution is as follows:

The DNS Client and DHCP Client are started by the DNS Clientand DHCP Client in the control panel, the management tool, andset to automatic

These two services are disabled after some optimization

software optimization.

IPConfi g

The IPConfig utility and its equivalent graphical userinterface - WinIPCfg in Windows 95/98 can be used to displaySettings for the current TCP/IP configuration. Thisinformation is commonly used to verify that the TCP/IP Settingsfor human configuration are correct. However,

If you use the computer local area network (LAN) and the DynamicHost Configuration Protocol (Dynamic Host ConfigurationProtocol, DHCP - under the Windows NT a distributing the lessIP address to Host more use agreement, similar to thedistribution of Dynamic IP dial-up) , the information displayedby the program may be more practical. At this point, IPConfiglets you know if your computer is successfully leased to an IPaddress, and if you rent it, you can see what the address iscurrently allocated. Knowing the current IP address, subnetmask, and default gateway is actually a necessary project fortesting and troubleshooting.

The most commonly used options:

Ipconfig--when using ipconf ig without any parameter options,it displays IP addresses, subnet masks, and default gatewayvalues for each configured interface

Ipconfig/all-when using all options, ipconfig for DNS andWINSserver shows that it has been configured to use the additionalinformation (such as IP address, etc. ) , and placed in the local

network adapter according to the physical address (MAC) . If theIP address from a DHCP server lease, IPConfig will display theIP address of the DHCP server and rent is expected to addressfailure date (please see the relevant contents about the DHCPserver other books on NT server, or ask your network management) ,the lower part of the output information as shown in figure 6.Ipconfig/release and ipconfig/renew -- these are twoadditional options that can only work on a computer that rentsits IPaddress to theDHCP server. If you enter ipconfig/release,the leased IP address of all the interfaces is redelivered tothe DHCP server (returning the IP address) . If you enteripconfig/renew, the local computer tries to contact the DHCPserver and rents an IP address. Note that in most cases, thenetwork card will be given the same IP address as previouslyassi gned.

If you are using a Windows 95/98, then you should be moreaccustomed to using winipcfg not ipconfig, because it is agraphical user interface, and show the same information withipconfig, and also offers the option of release and update thedynamic IP address if you purchased Windows NT Resource Kit (NTResource package) , then the Windows NT also includes agraphical alternative interface, the names of the utility iswntipcfg, and Windows 95/98 winipcfg similar.