Sometimes when my VPN connection to work goes down, certain applications that rely on intranet servers (e.g. Lotus Notes, Lotus Sametime) become unable to reconnect to their servers even after I reconnect to VPN. This is due to the operating system’s DNS lookup cache reusing the failed hostname lookup from when VPN was down rather than doing a fresh hostname lookup now that there is a fresh VPN connection.
On Windows, you can fix the issue by opening up the Command Prompt as Administrator and running the following command:
ipconfig /flushdns
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