The binding process in server-list mode works as follows:
Any program, running on the NIS client machine that needs information provided by an NIS map, asks ypbind for the name of a server.
The ypbind daemon looks in the /var/yp/binding/domainname/ypservers file for a list of NIS servers for the domain.
The ypbind daemon initiates binding to the first server in the list. If the server does not respond, ypbind tries the second, and so on, until it finds a server or exhausts the list.
The ypbind daemon tells the client process which server to talk to. The client then sends the request directly to the server.
The ypserv daemon on the NIS server handles the request by consulting the appropriate map.
The ypserv daemon sends the requested information back to the client.