System Administration Guide: Naming and Directory Services (DNS, NIS, and LDAP)

Network or Servers Are Overloaded

NIS can hang if the network or NIS servers are so overloaded that ypserv cannot get a response back to the client ypbind process within the time-out period.

Under these circumstances, every client on the network experiences the same or similar problems. In most cases, the condition is temporary. The messages usually go away when the NIS server reboots and restarts ypserv, or when the load on the NIS servers or network itself decreases.