Network Information Services (NIS), developed by Sun Microsystems with an original name of Yellow Page, is a network naming and administration system to centralize management of UNIX systems. NIS+ is a later version that provides additional security and other facilities. It has now essentially become an industry standard. All major UNIX like systems (Solaris, HP-UX, AIX, Linux, NetBSD, OpenBSD, FreeBSD, etc) support NIS (and NIS+).
NIS uses the client/server model and the Remote Procedure Call (RPC) interface for communication between hosts. NIS consists of a server, a library of client programs, and some administrative tools. NIS is often used with the Network File System (NFS). Using NIS, each host client or server computer in the system has knowledge about the entire system. A user at any host can get access to files or applications on any host in the network with a single user identification and password. NIS is similar to the Internet's domain name system (DNS) but somewhat simpler and designed for a smaller network. It's intended for use on local area networks.
The key terms of NIS are listed as follows:
| Term | Description |
| NIS domainname | An NIS master server and all of its clients (including its slave servers) have a NIS domainname. (The NIS domainname does not have anything to do with DNS.) |
| portmap | It must be running in order to enable RPC (Remote Procedure Call). If portmap is not running, it will be impossible to run an NIS server, or to act as an NIS client. |
| ypbind | ypbind is the core of client-server communication in an NIS environment. It ``Binds'' an NIS client to its NIS server. It will take the NIS domainname from the system, and using RPC, connect to the server. |
| ypserv | It should only be running on NIS servers; this is the NIS server process itself. If ypserv(8) dies, then the server will no longer be able to respond to NIS requests. |
| rpc.yppasswdd | It should only be running on NIS master servers; this is a daemon that will allow NIS clients to change their NIS passwords. If this daemon is not running, users will have to login to the NIS master server and change their passwords there. |
Related Terms: Unix, Client/Server model, Remote Procedure Call, Solaris, HP-UX, AIX, Linux, NetBSD, OpenBSD, FreeBSD
Reference Links: www.tldp.org/LDP/nag/node130.html: NIS: The Network Information system