nsswitch.conf.4 (2010 09)

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action and status names are case-insensitive.

The default criteria are to continue on anything except

SUCCESS; in other words, [SUCCESS=return

NOTFOUND=continue UNAVAIL=continue TRYAGAIN=continue]

The default, or explicitly speciﬁed, criteria are meaningless following the last source in an entry; and are

ignored since the action is always to return to the caller irrespective of the status code the source returns.

Interaction with netconﬁg

In order to ensure that they all return consistent results based on the

inet family of entries, gethost-

byname(), getservbyname()

, and netdir_getbyname()

functions are all implemented in terms

of the same internal switch library functions. These functions obtain the system-wide source lookup policy

for

hosts and services based on the inet

family entries in netconfig().Forservices and

hosts only the "-" in the last column, which represents nametoaddr libraries, is supported.

NIS (YP) server in DNS-forwarding Mode

The NIS (YP) server can be run in "DNS-forwarding mode" (see rpc.nisd_resolv(1M)), where it forwards

lookup requests to DNS for host-names and host-addresses that do not exist in its database. In this case,

specifying

nis as a source for hosts is sufﬁcient to get DNS lookups;

dns need not be speciﬁed expli-

citly as a source.

Interaction with +/- syntax

Releases prior to HP-UX 10.30 did not have the name-service switch support for passwd and group but

did allow the user some policy control. In

/etc/passwd one could have entries of the form +

user

(include the speciﬁed user from NIS passwd.byname),

-user (exclude the speciﬁed user) and + (include

everything, except excluded users, from NIS passwd.byname). The desired behavior was often "every-

thing in the ﬁle followed by everything in NIS", expressed by a solitary

+ at the end of /etc/passwd.

The switch provides an alternative for this case (

passwd: files nis) that does not require

+ entries

/etc/passwd.

If this is not sufﬁcient, the

compat source provides full +/- semantics. It reads

/etc/passwd for

getpwnam() functions and, if it ﬁnds +/- entries, invokes an appropriate source. The only source sup-

ported by pseudo-database

passwd_compat is nis.

The

compat source also provides full +/- semantics for group; the relevant pseudo-database is

group_compat.

Useful Conﬁgurations

The compiled-in default entries for all databases use NIS (YP) as the enterprise level name-service and

are identical to those in the default conﬁguration of this ﬁle:

passwd: files nis

group: files nis

hosts: dns [NOTFOUND=return] nis [NOTFOUND=return] files

ipnodes: dns [NOTFOUND=return] nis [NOTFOUND=return] files

networks: nis [NOTFOUND=return] files

protocols: nis [NOTFOUND=return] files

rpc: nis [NOTFOUND=return] files

publickey: nis [NOTFOUND=return] files

netgroup: nis

automount: files nis

aliases: files nis

services: files nis

sendmailvars: files

The policy nis [NOTFOUND=return] files implies "if nis is UNAVAIL, continue on to files,

and if

nis returns NOTFOUND, return to the caller"; in other words, treat nis as the authoritative source

of information and try files only if nis is down.

Notes

The

shadow routines getspnam(), getspnam_r(), and getspent() do not follow the compiled-in

default behaviour for passwd database. These routines use files as default source, unless explicitly

speciﬁed in the /etc/nsswitch.conf ﬁle.

If compatibility with the

+/- syntax for passwd and group is required, simply modify the entries for

passwd and group to:

2 Hewlett-Packard Company − 2 − HP-UX 11i Version 3: September 2010