You can disable resolver caching for applications in your
environment that do not need to use it.
Before you begin
Some applications might not need to use resolver caching.
For example, as shown in
Figure 1,
you might have a production network and a test network in your environment.
Users of the test network might require specialized host name resolution
using a unique set of DNS servers that are not used in the production
network. Because the test network is isolated and is likely to affect
only a small number of users, using resolver caching for the test
network could waste cache storage, and could complicate operation
of the production network by adding information that is not pertinent
to the production network. You can disable resolver caching for applications
using the test network, while continuing to use resolver caching for
the production network.
Procedure
Perform the following steps to disable caching for some
applications:
- Identify or create the TCPIP.DATA data set associated with
the application for which you want to disable resolver caching.
- Turn off the resolver caching function by specifying the
NOCACHE statement in that TCPIP.DATA data set.
- Issue the MODIFY RESOLVER,REFRESH command to cause the
resolver to refresh the settings for the application.
- Activate the trace resolver facility to determine which
TCPIP.DATA values are being used by the resolver and where they are
being read from.
- When the trace is active, issue the Netstat HOME⁄-h command
to display the values.