.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
.BR exportfs
understands the following export options:
.TP
-.IR secure "\*d
+.IR secure
This option requires that requests originate on an Internet port less
than IPPORT_RESERVED (1024). This option is on by default. To turn it
off, specify
.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
.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),