3.4 Configuring DNS Transport Parameters

You can fine-tune some of the parameters used by the Domain Name System (DNS) Resolver of the Novell BorderManager server.

To configure Transport parameters:

  1. Log in to iManager.

  2. Select Novell BorderManager > Proxy Services.

  3. Browse to and select the BorderManager server or container that you want to configure, then click OK.

  4. Select DNS from the General section.

    DNS Transport Protocol Configuration

  5. Specify values for the following parameters:

    Negative DNS Lookup: How long a failed DNS lookup domain name remains in the proxy server cache. If the proxy server cannot resolve a domain name, it stores that information in its cache for the specified amount of time.

    If the proxy server receives requests for that domain name within this period, it will send a Bad Gateway error message to the browser and does not resolve the domain name again.

    Maximum DNS Entry TTL: The maximum amount of time that DNS entries are cached before they expire. This is the maximum value, regardless of the value returned by the DNS name server.

    Minimum DNS Entry TTL: The minimum amount of time that DNS entries are cached before they expire. This is the minimum value, regardless of the value returned by the DNS name server.

    Maximum DNS Entry Threshold: The maximum number of DNS cache entries. When this number is reached, the proxy server deletes old entries to make room for newer ones. The default is 2,500.

  6. (Optional) Click Restore to Default to restore the default values.

  7. Click OK.

  8. Click Apply Changes to save the changes.