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8x8 Support

ContactNow: Softphone (X-Lite, Zoiper) won't connect to the dialer


A number of problems and error messages can be encountered while using a softphone. If you are experiencing difficulty getting your softphone to log on, you might receive a 403 error or the softphone simply won't connect to the dialer. Sometimes an IP address to a site may change.

If the DNS Resolver Cache has the old IP address record, it may result in your computer not being able to reach the site. Cached data can also become corrupt. Therefore, clearing it is a step you can take whenever you cannot connect to a site.

Often, the quickest way of resolving these problems is to re-install the software by using the Installation Wizard. If, after checking all your settings and you are sure they are correct, then the problem is probably being caused by your connection (firewall or router). Flushing the DNS cache clears all entries and reloads the entries from the Hosts file, which usually will fix any.

These DNS cache entries are known as DNS resource records, and the DNS resolver always checks the local cache before it queries the DNS server. We can easily solve this by removing cache data by flushing it. We will use the ipconfig command for this operation. We need to get administrator privileges to issue this command.


Please note: before proceeding please consult your local IT person.

Applies To

  • ContactNow
  • Softphone (X-lite, Zoiper)


Option 1

The first step to flushing your DNS is to open your “Windows Command” prompt.

  • WinXP: Start Run > type cmd > press Enter.
  • Vista, Window 7 and Windows 8: Click Start type Command in the Start search field.

In the open prompt, type ipconfig /flushdns.

ipconfig /flushdns

Completely close the softphone and try connecting again.


Option 2

To reset the DNS resolver cache, perform the following steps:

  1. Select the Start button, then type cmd.
  2. Right-click Command Prompt, choose Run as Administrator.
  3. Type ipconfig /flushdns then press Enter (be sure there is a space before the slash).
    Windows Flush DNS command

A command box will flash on the screen for a split second and the DNS Resolver cache is cleared.


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