Configure the domain used for the sitemap generation
Use this procedure to configure which domain is used in the generation of the sitemap when you have a load balanced scenario. The desired setup would be to use the domain, instead of the IP address of the particular node.
To do this, perform the following:
    - Navigate to Administration » Settings » Advanced.
 
    - In the left pane, expand System and click Site URL Settings.
 
    - Select Enable non-default Site URL Settings checkbox.
 
    - In The Host field, enter the domain that you want to be used for sitemap generation.
 
    - Save your changes.
 
    - Restart the application.
 
    - Regenerate the sitemap by navigating to Administration » Sitemap » Generate Now.