Using NIS to maintain host information

Advantage of using NIS

Like DNS, NIS enables you to centrally maintain host information. NIS provides two methods for filer host name resolution:

A makefile master on the NIS server, which creates an /etc/hosts file and copies it to the filers default volume for local host name lookup
This method is described in Creating /etc/hosts from the NIS master.
A host map, maintained as a database on the NIS server, which the filer queries in a host lookup request across the network
This method is described in the following sections.

NIS also enables you to maintain user information. For more information, see the Storage Management Guide.

About configuring NIS for host lookups

You can configure the filer to use one or more NIS servers either during the setup procedure or later using the Data ONTAP command line or FilerView.

If you configure NIS later, you need to do all of the following:

Specify the NIS server to which the filer should bind
Specify the NIS domain name of the filer
Enable NIS on the filer

You can enable NIS and set NIS configuration values in either of these ways:

Using FilerView
See Configuring NIS with FilerView.
At the command line
See the appropriate instructions:

If you want to use primarily NIS for host-name resolution, specify it ahead of other methods in the hosts map in the /etc/nsswitch.conf file. For information about how to edit the nsswitch.conf file, see Changing the host name search order.

Correct host-name resolution depends on the correct configuration of the NIS server. If you experience problems with host-name resolution or data availability, check the NIS server in addition to local networking.

For more information about the filer NIS client, see the NetApp nis(8) manual page.

Configuring NIS with FilerView

To set or modify NIS configuration values with FilerView, complete the following steps.

Step	Action
1	In FilerView, click Network in the list on the left.
2	In the list under Network, click Manage DNS and NIS Name Service.
3	If you want to....	Then...
	Enable or disable NIS	Select Yes or No in the NIS Enabled field.
	Set or modify the NIS domain name	Enter a name in the NIS Domain Name field. Examples of configuration values are listed in Specifying the NIS domain name.
	Specify or modify NIS servers	Enter one or more IP addresses in the NIS Servers fields. Examples of configuration values are listed in Specifying NIS servers to bind to.

For information about NIS group cache updates, see the Storage Management Guide.

Specifying NIS servers to bind to

You can specify an ordered list of NIS servers to which you want the filer to bind. The list should begin with the closest NIS server (closest in network terms) and end with the furthest one.

To specify an ordered list of NIS servers you want the filer to bind to, complete the following step.

Note
You can specify NIS servers by IP address or host name. If host names are used, make sure each host name along with its IP address is listed in the /etc/hosts file. Otherwise, the binding with host name will fail.

Step	Action
1	Enter the following command to specify the NIS servers and their order: options nis.servers ip_address,server_name,* The asterisk () specifies that broadcast is used to bind to NIS servers if the servers in the list are not responding. This is the default. If you do not specify broadcasting (that is, no asterisk) and none of the listed servers are responding, NIS services are disrupted until one of the preferred servers responds. Caution* Using the NIS broadcast feature can incur security risks.

Step

Action

Enter the following command to specify the NIS servers and their order:

options nis.servers ip_address,server_name,*

The asterisk (*) specifies that broadcast is used to bind to NIS servers if the servers in the list are not responding. This is the default. If you do not specify broadcasting (that is, no asterisk) and none of the listed servers are responding, NIS services are disrupted until one of the preferred servers responds.

Caution
Using the NIS broadcast feature can incur security risks.

Example of specifying NIS servers to bind to

The following lists two servers and uses the broadcast default:

options nis.servers 172.15.16.1,nisserver-1,*

The filer first tries to bind to 172.15.16.1. If the binding fails, the filer tries to bind to nisserver-1. If this binding fails also, the filer binds to any server that responds to the broadcast. While bound to the NIS server that responded to the broadcast, the filer continues to poll the preferred servers. As soon as one of the preferred servers is found, the filer binds to the preferred server.

Specifying the NIS domain name

To specify the NIS domain name, complete the following step.

Step	Action
1	Enter the following command: options nis.domainname domain domain is the NIS domain name to which the filer belongs; for example, typical NIS domain names might be sales or marketing. The NIS domain name is not usually the same as the DNS domain name.

Enabling or disabling NIS

To enable or disable NIS on your filer, complete the following step.

Step	Action
1	Enter the following command: options nis.enable {on\|off} Use `on` to enable and `off` to disable NIS.

Displaying NIS information

You can display the following types of NIS information:

NIS domain name
Last time the local group cache was updated
The following information about each NIS server that was polled by the filer:
- IP address of the NIS server
- Type of NIS server
- State of the NIS server
- Whether the filer is bound to the NIS server
- Time of polling

To display NIS information, complete the following step.

Step	Action
1	Enter the following command: nis info

For more information about the nis info command and resulting display, see the NetApp nis(1) manual page.

NIS administrative commands

Data ONTAP supports the standard NIS administrative commands listed in the following table. For more information, see each command's manual page.

Command	Function
`ypcat`	Prints an entire NIS map
`ypgroup`	Displays the NIS group cache entries
`ypmatch`	Looks up specific entries in an NIS map
`ypwhich`	Returns the name of the current NIS server