1IRS.CONF(5)                 BSD File Formats Manual                IRS.CONF(5)
2

NAME

4     irs.conf — Information Retrieval System configuration file
5

SYNOPSIS

7     irs.conf
8

DESCRIPTION

10     The irs(3) functions are a set of routines in the C library which provide
11     access to various system maps.  The maps that irs currently controls are
12     the following: passwd, group, services, protocols, hosts, networks and
13     netgroup.  When a program first calls a function that accesses one of
14     these maps, the irs configuration file is read, and the source of each
15     map is determined for the life of the process.
16
17     If this file does not exist, the irs routines default to using local
18     sources for all information, with the exception of the host and networks
19     maps, which use the Domain Name System (DNS).
20
21     Each record in the file consists of one line.  A record consists of a
22     map-name, an access-method and possibly a (comma delimited) set of
23     options, separated by tabs or spaces.  Blank lines, and text between a #
24     and a newline are ignored.
25
26     Available maps:
27
28           Map name        Information in map
29           =========       ==================================
30           passwd          User authentication information
31           group           User group membership information
32           services        Network services directory
33           protocols       Network protocols directory
34           hosts           Network hosts directory
35           networks        Network "network names" directory
36           netgroup        Network "host groups" directory
37
38     Available access methods:
39
40           Access method   Description
41           =============   =================================================
42           local           Use a local file, usually in /etc
43           dns             Use the domain name service (includes hesiod)
44           nis             Use the Sun-compatible Network Information Service
45           irp             Use the IRP daemon on the localhost.
46
47     Available options:
48
49           Option          Description
50           ========        ================================================
51           continue        don't stop searching if you can't find something
52           merge           don't stop searching if you CAN find something
53
54     The continue option creates “union namespaces” whereby subsequent access
55     methods of the same map type can be tried if a name cannot be found using
56     earlier access methods.  This can be quite confusing in the case of host
57     names, since the name to address and address to name mappings can be vis‐
58     ibly asymmetric even though the data used by any given access method is
59     entirely consistent.  This behavior is, therefore, not the default.
60
61     The merge option only affects lookups in the groups map.  If set, subse‐
62     quent access methods will be tried in order to cause local users to
63     appear in NIS (or other remote) groups in addition to the local groups.
64

EXAMPLE

66           # Get password entries from local file, or failing that, NIS
67           passwd          local   continue
68           passwd          nis
69
70           # Build group membership from both local file, and NIS.
71           group           local   continue,merge
72           group           nis
73
74           # Services comes from just the local file.
75           services        local
76
77           protocols       local
78
79           # Hosts comes first from DNS, failing that, the local file
80           hosts           dns     continue
81           hosts           local
82
83           # Networks comes first from the local file, and failing
84           # that the, irp daemon
85           networks        local   continue
86           networks        irp
87
88           netgroup        local
89

NOTES

91     If a local user needs to be in the local host's “wheel” group but not in
92     every host's “wheel” group, put them in the local host's /etc/group
93     “wheel” entry and set up the “groups” portion of your /etc/irs.conf file
94     as:
95
96           group   local   continue,merge
97           group   nis
98
99     NIS takes a long time to time out.  Especially for hosts if you use the
100     -d option to your server's “ypserv” daemon.
101
102     It is important that the irs.conf file contain an entry for each map.  If
103     a map is not mentioned in the irs.conf file, all queries to that map will
104     fail.
105
106     The classic NIS mechanism for specifying union namespaces is to add an
107     entry to a local map file whose name is ``+''.  In IRS, this is done via
108     ``continue'' and/or ``merge'' map options.  While this results in a small
109     incompatibility when local map files are imported from non-IRS systems to
110     IRS systems, there are compensating advantages in security and configura‐
111     bility.
112

FILES

114     /etc/irs.conf      The file irs.conf resides in /etc.
115

SEE ALSO

117     groups(5), hosts(5), netgroup(5), networks(5), passwd(5), protocols(5),
118     services(5)
119
120BIND 8.1                       November 16, 1997                      BIND 8.1
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