What is the difference between dns and nis domain

Each domain is supported by two or more name servers , a principal server and one or more secondary servers. Each server implements DNS by running a daemon called in.

On the client's side, DNS is implemented through the "resolver. It queries a name server, which then returns either the requested information or a referral to another server. Many old UNIX operating systems and machines still use this system, but it is not well suited for large complex networks.

Whereas DNS focuses on making communication simpler by using machine names instead of numerical IP addresses, NIS focuses on making network administration more manageable by providing centralized control over a variety of network information. NIS stores information about machine names and addresses, users, the network itself, and network services.

Establishing a Security Framework. Securing Red Hat Linux. Securing the Host. Securing the Network. Performing Security Audits. Keeping up with Security News and Updates.

Chapter Software Development in Linux. Software Development Tools in Linux. The GNU Debugger. Implications of GNU Licenses.

Version Control. Linux Programming Topics. Chapter Shell and Perl Scripting. Looking at Some Shell Scripts. Learning the Basics of Shell Scripting in Bash. Perl as a Scripting Language. Introducing Tcl. Introducing Tk. Chapter Java Programming. Getting Ready for Java Programming. Writing Your First Java Program. Learning Java. Writing Java Servlets. Becoming Proficient in Java. Part VI: Appendixes. Appendix A: Linux Commands. Appendix B: Disk Drives.

Disk Drive Concepts. Floppy Disks in Linux. Hard Disk Operations in Linux. Appendix D: Ethernet Cards. Supported Ethernet Cards. Ethernet Driver Modules.

Ethernet Autoprobing. Multiple Ethernet Cards. Appendix E: Modems and Terminals. Linux and Modems. Setting up Linux for Dial-In. Terminals and Multiport Serial Boards. Appendix F: PC Cards. Appendix G: Linux Resources. FTP Archive Sites. System Requirements. Source Code Coupon. List of Figures. List of Tables. List of Code Examples. List of Sidebars. NIS uses a client-server arrangement. The principal servers are called master servers, and for reliability, they have backup, or slave servers.

NIS uses domains to arrange the machines, users, and networks in its namespace. However, it does not use a domain hierarchy; an NIS namespace is flat.

The Solaris operating environment also allows you to set up the nsswitch. Servers are also clients, typically of themselves. NIS servers come in two varieties, master and slave.

The machine designated as master server contains the set of maps that the system administrator creates and updates as necessary. Each NIS domain must have one, and only one, master server, which can propagate NIS updates with the least performance degradation. You can designate additional NIS servers in the domain as slave servers. A slave server has a complete copy of the master set of NIS maps. Whenever the master server maps are updated, the updates are propagated among the slave servers.

Normally, the system administrator designates one master server for all NIS maps. However, because each individual NIS map has the machine name of the master server encoded within it, you could designate different servers to act as master and slave servers for different maps. To minimize confusion, designate a single server as the master for all the maps you create within a single domain. The examples in this chapter assume that one server is the master for all maps in the domain. NIS clients run processes that request data from maps on the servers.

Clients do not make a distinction between master and slave servers, since all NIS servers should have the same information. Each domain has a domain name and each machine sharing the common set of maps belongs to that domain. Any machine can belong to a given domain, as long as there is a server for that domain's maps in the same network. NIS service is provided by five daemons as shown in Table 7—1. This means that users who have a shell that begins with an r. If you have a shell that begins with r but is not intended to be restricted as such, refer to Chapter 10, NIS Troubleshooting for the workaround.

NIS service is supported by nine utilities as shown in Table 7—2. The information in NIS maps is stored in ndbm format. NIS slave servers also maintain duplicates of the master server's maps. NIS client machines can obtain namespace information from either master or slave servers.

NIS maps are essentially two-column tables. One column is the key and the other column is information related to the key. NIS finds information for a client by searching through the keys.

Some information is stored in several maps because each map uses a different key. For example, the names and addresses of machines are stored in two maps: hosts. When a server has a machine's name and needs to find its address, it looks in the hosts.

When it has the address and needs to find the name, it looks in the hosts. Running make in that directory causes makedbm to create or modify the default NIS maps from the input files. Always create maps on the master server, as maps created on a slave will not automatically be pushed to the master server. A default set of NIS maps are provided in the Solaris operating environment. You might want to use all these maps or only some of them. NIS can also use whatever maps you create or add when you install other software products.

For example, the maps that belong to the domain test. Table 7—3 describes the default NIS maps, information they contain, and whether the software consults the corresponding administrative files when NIS is running. Same as ethers. Used for UNIX-style authentication. Contains machine name and mail address including domain name. If there is a netid file available it is consulted in addition to the data available through the other files. Contains names of networks known to your system and their IP addresses, with the address as key.

New ipnodes maps ipnodes. The maps store both IPv4 and IPv6 addresses. See the ipnodes 4 man page. For example, when you add a new machine to a network running NIS, you only have to update the input file in the master server and run make.

This automatically updates the hosts. These maps are then transferred to any slave servers and are made available to all of the domain's client machines and their programs. When a client machine or application requests a machine name or address, the NIS server refers to the hosts. You can use the ypcat command to display the values in a map.

The ypcat basic format is the following. If a map is composed only of keys, as in the case of ypservers , use ypcat -k. Otherwise, ypcat prints blank lines.