The Clear DNS Cache option (available as part of Node Level Settings), clears or flushes the DNS cache on the SBC. All subsequent DNS queries are sent to the configured DNS servers, and the DNS cache is updated.
This operation is required only as a diagnostic tool when DNS TTL related issues are suspected.
Clear DNS Cache as follows:
In the left navigation pane, go to System > Node-Level Settings.
At the top of the page, click Clear DNS Cache.
From the confirmation dialog box, click OK. The DNS cache is cleared.
For details on the Node-Level Setting screen, see Configuring Host Information and DNS.