Customize SharePoint URL using AAM and DNS

1. Configure DNS

• Open DNS Manager
• Navigate to respective forward lookup zone.
• Create a CNAME record by right clicking  in the zone and selecting “New Alias (CNAME)”

Select relative host record of the CNAME.

        

Once you add the CNAME you can see an entry as below.


Update Group Policy
Make sure you run a Group Policy update after adding the record.
       
Check connectivity from CNAME record
And then you can check whether the CNAME is being resolved.  You can monitor that CNAME is being resolved.
       
2. Configure IIS

If the web application is hosted in port 80 you don’t have to edit the IIS host header as you will be redirected to port 80 when enter the CNAME.
If you are using a different port other that 80 you might have to IIS website.

• To add an entry right click the web site in IIS manager, then select edit bindings.

    

• Add Host name and Port. Note that you should CNAME record and the Host Name should be identical.

    
3. Add Alternate Access Mapping in SharePoint Central Administration
Central Administration -> Application Management -> Configure Alternate Access Mapping -> Edit Public URLs
Select the web Application, then add the URL to Preferred zone.
    
Now you can access SharePoint site by entering the Customized URL (CNAME).