How to change Internet Explorer DNS Cache , KeepAlive and Server Info Timeouts

David Kingsland asks here about changing the Internet Explorer default DNS Cache.

Changing the DNS Cache Timeout

The default DNS Cache timeout can be changed through the following method:

1. Start Registry Editor.
2. Locate and click the following key in the registry:
HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsCurrentVersionInternet Settings
3. On the Edit menu, click Add Value, and then add the following registry values:
Value Name: DnsCacheTimeout
Data Type: REG_DWORD
Radix: Decimal
Value: (time in seconds)Value Name: ServerInfoTimeOut
Data Type: REG_DWORD
Radix: Decimal
Value: (time in seconds)
4. Quit Registry Editor.For example, to set the time-out value to 10 minutes, use a value of 600 seconds.
Note You must use both the registry values listed in step 3 to control the Internet Explorer internal resolver cache mechanism.

Here is the Microsoft article describing all this.

Changing the KeepAlive Timeout

1. Click Start, click Run, type regedit, and then click OK.
2. Locate and then click the following key in the registry:
HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionInternetSettings
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type KeepAliveTimeout, and then press ENTER.
5. On the Edit menu, click Modify.
6. Type the appropriate time-out value (in milliseconds), and then click OK. For example, to set the time-out value to two minutes, type 120000.
7. Restart Internet Explorer.

If you set the KeepAliveTimeout value to less than 60,000 (one minute), you may have problems communicating with Web servers that require persistent HTTP connections. For example, you may receive a “Page cannot be displayed” error message.

If you must have a KeepAliveTimeout value higher than 120000 (two minutes), you must create an additional registry key and set its value equal to the KeepAliveTimeout value that you want. The additional registry key is ServerInfoTimeout. It is a DWORD with a value (in milliseconds) and in the same location as KeepAliveTimeout.

For example, to use a three-minute KeepAliveTimeout value, you must create the following registry keys:
HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionInternetSettings

KeepAliveTimeout DWORD value 180000 (in milliseconds)
ServerInfoTimeout DWORD value 180000 (in milliseconds)
By default, HTTP 1.1 is enabled in Internet Explorer except when you establish an HTTP connection through a proxy server. When HTTP 1.1 is enabled, HTTP connections remain open (or persistent) by default until the connection is idle for one minute or until the value that is specified by the KeepAliveTimeout value in the registry is reached. You can modify HTTP 1.1 settings in Internet Explorer by using the Advanced tab in the Internet Options dialog box.

Here is the Microsoft article describing all this.

Changing the Server Info Timeout

1. Click Start, click Run, type regedit, and then click OK.
2. Locate and then click the following key in the registry:
HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionInternetSettings
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type KeepAliveTimeout, and then press ENTER.
5. On the Edit menu, click Modify.
6. Type the appropriate time-out value (in milliseconds), and then click OK. For example, to set the time-out value to two minutes, type 120000.
7. Restart Internet Explorer.

If you set the KeepAliveTimeout value to less than 60,000 (one minute), you may have problems communicating with Web servers that require persistent HTTP connections. For example, you may receive a “Page cannot be displayed” error message.

If you must have a KeepAliveTimeout value higher than 120000 (two minutes), you must create an additional registry key and set its value equal to the KeepAliveTimeout value that you want. The additional registry key is ServerInfoTimeout. It is a DWORD with a value (in milliseconds) and in the same location as KeepAliveTimeout.

For example, to use a three-minute KeepAliveTimeout value, you must create the following registry keys:
HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionInternetSettings

KeepAliveTimeout DWORD value 180000 (in milliseconds)
ServerInfoTimeout DWORD value 180000 (in milliseconds)
By default, HTTP 1.1 is enabled in Internet Explorer except when you establish an HTTP connection through a proxy server. When HTTP 1.1 is enabled, HTTP connections remain open (or persistent) by default until the connection is idle for one minute or until the value that is specified by the KeepAliveTimeout value in the registry is reached. You can modify HTTP 1.1 settings in Internet Explorer by using the Advanced tab in the Internet Options dialog box.

Here is the Microsoft article describing all this.

My Recommendation

I would recommend that you should not change these values unless you are an advanced user and you should always backup your registry before playing with the registry editor.

And instead of doing it manually, here is a cool utility that lets you automatically change the values. Please use this tool instead of the registry tweaks.

Download IE Timeout Tuner