Internet Explorer does a DNS Caching which is different from that of the DNS caching on the system through the DNS Client or Resolvers. By default Internet Explorer caches DNS Answers or Responses for 30 minutes. However, this can be controlled or fine tuned from the registry to suit the organisation needs as a regular update means increased network traffic or for a home user who feels this time period is too long and has to be reduced. The DNS CACHING entries for Internet Explorer are found in the following Registry Key:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings
The values of interest are,
DnsCacheTimeout
ServerInfoTimeOut
To set these values,
1. Click Start – RUN.
2. Type REGEDIT and press ENTER. This will open Windows Registry Editor with the Keys in the Left pane and the Values in the Right pane.
3. Navigate to
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings
in the left pane.
4. In the Right pane, check if the value DnsCacheTimeOut is found.
5. If found, right-click and select Modify. Select Decimal under Base and change the value as required seconds and click OK.
6. If not found, right-click in the right pane, click New – DWORD and name it as DnsCacheTimeOut.
7. Right-click the newly added value, select Decimal under Base and enter the value as required in seconds and click OK.
8. Repeat steps 1 through 6 to set the ServerInfoTimeOut
NOTE: This DNS Caching is different from that of the DNS Caching done by the DNS Client or Resolver on the system.