NIS+ Transition Guide

Deciding How to Implement DNS Forwarding

NIS servers can forward DNS requests made from Solaris 1.x NIS clients. NIS+ servers running in NIS-compatibility mode also provide DNS forwarding, starting with the Solaris 2.3 or later releases. (This feature is available in the Solaris 2.2 release patch #101022-06.) As a result, NIS clients, runnig under the Solaris 2 or Solaris 7 operating environment, must have appropriate /etc/nsswitch.conf and /etc/resolv.conf files installed locally.

Solaris 1.x NIS clients supported by Solaris 2.0 or 2.1 servers running in NIS-compatibility mode are not able to take advantage of DNS forwarding. You must upgrade those servers to Solaris 2.3 (or later) releases.

If the DNS domains are repartitioned, you must redefine new DNS zone files. Clients, however, may require updates to their /etc/resolv.conf file. A client, if it is also a DNS client, can set up its name service switch configuration file to search for host information in either DNS zone files or NIS maps--in addition to NIS+ tables.

DNS Forwarding for NIS+ Clients

NIS+ clients do not have implicit DNS-forwarding capabilities like NIS clients do. Instead, they take advantage of the name service switch. To provide DNS capabilities to an NIS+ client, change its hosts entry to:

hosts: nisplus dns [NOTFOUND=return] files

DNS Forwarding for NIS Clients Running under the Solaris 2 or Solaris 7 Operating Environment

If an NIS client is using the DNS forwarding capability of an NIS-compatible NIS+ server, the client's nsswitch.conf file should not have the following syntax in the hosts file:

hosts: nis dns files
Since DNS-forwarding automatically forwards host requests to DNS, this syntax causes both the NIS+ server and the name service switch to forward unsuccessful requests to the DNS servers, slowing performance.