How to Share SharePoint 2013 sub-site with external users

Question

If I try to add external users other than my domain I am getting an error "you are not allowed to add external user". I could not find any settings in central admin. There are settings instruction for SharePoint online or office365 available on the web. Kindly help on this.

Answer 1

SharePoint On-premises doesn’t have feature to share sites with external users by default.

We need to extend the web application and implement identity providers such as ADFS.