When you are connecting to a SharePoint server, you’re redirected to the default website (for IIS7 you will see the IIS7 image).
IIS can listen on port 80 for multiple websites. If the given hostname corresponds with the configured binding in IIS, IIS will show the correct website. But SharePoint only listens on the hostnames which are configured within the alternate access mappings. Follow the steps below to configure the bindings in IIS and alternate access mappings within SharePoint.
Configure bindings IIS manager
1. Open the IIS manager (Start > Run > inetmgr)
2. In Sites, right-click the SharePoint site and click Edit Bindings…
4. Type the host name of the corresponding name in DNS.
Set alternate access mappings SharePoint
1. Open you SharePoint Central Administration site
2. On the main page, click Configure alternate access mappings
3. Click on Edit Public URLs or Add Internal URLs if none are defined yet
4. Type the URL in the field Default. You could also fill in the other fields, like Internet or Extranet when your SharePoint site is published to the outside world.