Citrix Xenserver Networking

     http://support.citrix.com/servlet/KbServlet/download/17424-102-671540/Xen_Networking_in_Linux_final.pdf

• In this setup, the bridge is also seen as an interface. If it‟s joining members of an external network together, its name will begin with “xenbr”, the “br” meaning bridge. 

• If it‟s joining members of an internal network  together, its name will being with “xapi”.