.SS Machine Name Formats
NFS clients may be specified in a number of ways:
.IP "single host
-This is the most common format. You may specify a host either by an
+You may specify a host either by an
abbreviated name recognized be the resolver, the fully qualified domain
-name, or an IP address.
-.IP "netgroups
-NIS netgroups may be given as
-.IR @group .
-Only the host part of each
-netgroup members is consider in checking for membership. Empty host
-parts or those containing a single dash (\-) are ignored.
-.IP "wildcards
-Machine names may contain the wildcard characters \fI*\fR and \fI?\fR.
-This can be used to make the \fIexports\fR file more compact; for instance,
-\fI*.cs.foo.edu\fR matches all hosts in the domain
-\fIcs.foo.edu\fR. As these characters also match the dots in a domain
-name, the given pattern will also match all hosts within any subdomain
-of \fIcs.foo.edu\fR.
+name, an IPv4 address, or an IPv6 address. IPv6 addresses must not be
+inside square brackets in /etc/exports lest they be confused with
+character-class wildcard matches.
.IP "IP networks
You can also export directories to all hosts on an IP (sub-) network
simultaneously. This is done by specifying an IP address and netmask pair
where the netmask can be specified in dotted-decimal format, or as a
contiguous mask length.
For example, either `/255.255.252.0' or `/22' appended
-to the network base IPv4 address results in identical subnetworks with 10 bits of
-host. Wildcard characters generally do not work on IP addresses, though they
+to the network base IPv4 address results in identical subnetworks with 10 bits
+of host. IPv6 addresses must use a contiguous mask length and must not be inside square brackets to avoid confusion with character-class wildcards. Wildcard characters generally do not work on IP addresses, though they
may work by accident when reverse DNS lookups fail.
+.IP "wildcards
+Machine names may contain the wildcard characters \fI*\fR and \fI?\fR, or may contain character class lists within [square brackets].
+This can be used to make the \fIexports\fR file more compact; for instance,
+\fI*.cs.foo.edu\fR matches all hosts in the domain
+\fIcs.foo.edu\fR. As these characters also match the dots in a domain
+name, the given pattern will also match all hosts within any subdomain
+of \fIcs.foo.edu\fR.
+.IP "netgroups
+NIS netgroups may be given as
+.IR @group .
+Only the host part of each
+netgroup members is consider in checking for membership. Empty host
+parts or those containing a single dash (\-) are ignored.
+.IP "anonymous
+This is specified by a single
+.I *
+character (not to be confused with the
+.I wildcard
+entry above) and will match all clients.
'''.TP
'''.B =public
'''This is a special ``hostname'' that identifies the given directory name
'''.B \-\-public\-root
'''option. Multiple specifications of a public root will be ignored.
.PP
+If a client matches more than one of the specifications above, then
+the first match from the above list order takes precedence - regardless of
+the order they appear on the export line. However, if a client matches
+more than one of the same type of specification (e.g. two netgroups),
+then the first match from the order they appear on the export line takes
+precedence.
.SS RPCSEC_GSS security
You may use the special strings "gss/krb5", "gss/krb5i", or "gss/krb5p"
to restrict access to clients using rpcsec_gss security. However, this
.IR async
above).
-In releases of nfs-utils up to and including 1.0.0, this option was the
+In releases of nfs-utils up to and including 1.0.0, the
+.I async
+option was the
default. In all releases after 1.0.0,
.I sync
is the default, and
will be given this list of alternatives. (Note that actual replication
of the filesystem must be handled elsewhere.)
-.TP
-.IR refer= path@host[+host][:path@host[+host]]
-A client referencing the export point will be directed to choose from
-the given list an alternative location for the filesystem.
-(Note that the server must have a mountpoint here, though a different
-filesystem is not required; so, for example,
-.IR "mount --bind" " /path /path"
-is sufficient.)
-.TP
-.IR replicas= path@host[+host][:path@host[+host]]
-If the client asks for alternative locations for the export point, it
-will be given this list of alternatives. (Note that actual replication
-of the filesystem must be handled elsewhere.)
-
.SS User ID Mapping
.PP
.B nfsd
.B /home/joe
in the example section below, which maps all requests to uid 150 (which
is supposedly that of user joe).
+.SS Extra Export Tables
+After reading
+.I /etc/exports
+.B exportfs
+reads files under
+.I /etc/exports.d.
+directory as extra export tables.
+.B exportfs
+regards only a file which name is ended with
+.I .exports
+and
+not started with
+.I .
+as an extra export file. A file which name
+is not met this condition is just ignored.
+The format for extra export tables is the same as
+.I /etc/exports
+.
.IP
.SH EXAMPLE
.PP
/home/joe pc001(rw,all_squash,anonuid=150,anongid=100)
/pub *(ro,insecure,all_squash)
/srv/www \-sync,rw server @trusted @external(ro)
+/foo 2001:db8:9:e54::/64(rw) 192.0.2.0/24(rw)
+/build buildhost[0-9].local.domain(rw)
'''/pub/private (noaccess)
.fi
.PP
don't use a reserved port for NFS.
The sixth line exports a directory read-write to the machine 'server'
as well as the `@trusted' netgroup, and read-only to netgroup `@external',
-all three mounts with the `sync' option enabled.
+all three mounts with the `sync' option enabled. The seventh line exports
+a directory to both an IPv6 and an IPv4 subnet. The eighth line demonstrates
+a character class wildcard match.
''' The last line denies all NFS clients
'''access to the private directory.
'''.SH CAVEATS
'''entry.
.SH FILES
/etc/exports
+/etc/exports.d
.SH SEE ALSO
.BR exportfs (8),
.BR netgroup (5),
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