Name service (DNS, NIS)

Specifying the search order of name databases

This window specifies how the filer uses name service. To reload the current settings from the filer, click the Reload Settings button. To view the changes that you made, click the View Changes button. After you make a change, click the Save Changes button to save the changes to the filer.

Specifying the search order of name databases

The filer can use NIS (Network Information System) maps or database files on the filer to resolve names. For host names, the filer can also use DNS (domain name service). The buttons in this window show the order in which the database is searched. For example, for Hosts, if you select NIS, Files, and DNS, the filer first uses the NIS map to resolve a host name. If that fails, the filer uses the /etc/hosts file. If the filer still cannot resolve the name through the /etc/hosts file, it uses the DNS server.

The following list describes the fields in this window:

Hosts: Specifies how the filer resolves host names.
Passwd: Specifies how the filer searches the password database for determining user IDs.
Shadow: Specifies how the filer searches the shadow password database for encrypted password information and password aging information used in CIFS and (PC)NFS environments.
Group: Specifies how the filer searches the group database for determining user group IDs.
Netgroup: Specifies how the filer searches the netgroup database in an NFS environment.

Configuring DNS

The filer includes DNS client capabilities. This means that it can query DNS servers for host-name-to-IP-address and IP-address-to-host-name translation services. With DNS enabled, you no longer have to update the filer /etc/hosts file every time a new host is added to the network. However, if you specify that the filer searches the local file first, you still have to update the /etc/hosts file.

To prevent naming inconsistencies, when DNS is enabled, keep a minimum number of entries in the /etc/hosts file.

If you enable DNS, specify the DNS domain name and up to three IP addresses of domain name servers in this window.

Cluster considerations

In a cluster, the DNS Enabled field must have the same value on both filers and the Domain Name must be the same on both filers for takeover to occur properly.

Configuring NIS

The filer includes NIS client capabilities. This means that it can query NIS servers for host-name-to-IP-address and IP-address-to-host-name translation services.

The filer uses the following NIS maps:

hosts.byname
hosts.byaddr
passwd.byname
passwd.byuid
passwd.adjunct
group.byname
group.bygid
netgroup.byhost

Shadow password information is obtained from the passwd.byname map.

If you enable NIS, specify the NIS domain name in this window.

The Update Schedule value is a comma-separated list of hours when the NIS group files should be updated.

The Servers value is a comma-separated list of NIS servers. This list should be ordered from the closet to the furthest server. If hostnames (rather than IP addresses) are used, the names must be listed in /etc/hosts. The default value is "*" (broadcast). Here is an example value:

	nis.servers 172.15.16.1,nisserver-1,*

In this example, the filer will try to bind to 172.15.16.1. In case of failure, the filer will bind to nisserver-1. If this also fails, it will bind to any server that responds to the broadcast. While the filer is bound to a NIS server that is neither 172.15.16.1 nor nisserver-1, it will keep trying to bind itself to the preferred servers. Security conscious locations who don't want to fall back to broadcast can do so by not including '*' in the value.

Cluster considerations

In a cluster, the NIS Enabled field must have the same value on both filers and the Domain Name must be the same on both filers for takeover to occur properly.